Institute of Fundamental Technological Research
Polish Academy of Sciences

Staff

Maria Staszczak, PhD

Department of Experimental Mechanics (ZMD)
Division of Applied Thermomechanics (PTS)
position: Research Specialist
telephone: (+48) 22 826 12 81 ext.: 366
room: 040
e-mail:
ORCID: 0000-0002-2593-9482

Doctoral thesis
2019-10-03 Doświadczalna analiza termomechanicznych i funkcjonalnych właściwości wybranych poliuretanów z pamięcią kształtu 
supervisor -- Elżbieta Pieczyska, PhD, DSc, IPPT PAN
 

Recent publications
1.  Staszczak M., Urbański L., Gradys A. D., Cristea M., Pieczyska E. A., Nucleation, Development and Healing of Micro-Cracks in Shape Memory Polyurethane Subjected to Subsequent Tension Cycles, Polymers, ISSN: 2073-4360, DOI: 10.3390/polym16131930, Vol.16, No.13, pp.1-22, 2024

Abstract:
Thermoresponsive shape memory polymers (SMPs) have garnered increasing interest for their exceptional ability to retain a temporary shape and recover the original configuration through temperature changes, making them promising in various applications. The SMP shape change and recovery that happen due to a combination of mechanical loading and appropriate temperatures are related to its particular microstructure. The deformation process leads to the formation and growth of micro-cracks in the SMP structure, whereas the subsequent heating over its glass transition temperature Tg leads to the recovery of its original shape and properties. These processes also affect the SMP microstructure. In addition to the observed macroscopic shape recovery, the healing of micro-crazes and micro-cracks that have nucleated and developed during the loading occurs. Therefore, our study delves into the microscopic aspect, specifically addressing the healing of micro-cracks in the cyclic loading process. The proposed research concerns a thermoplastic polyurethane shape memory polymer (PU-SMP) MM4520 with a Tg of 45 °C. The objective of the study is to investigate the effect of the number of tensile loading-unloading cycles and thermal shape recovery on the evolution of the PU-SMP microstructure. To this end, comprehensive research starting from structural characterization of the initial state and at various stages of the PU-SMP mechanical loading was conducted. Dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS) and scanning electron microscopy (SEM) were used. Moreover, the shape memory behavior in the thermomechanical loading program was investigated. The obtained average shape fixity value was 99%, while the shape recovery was 92%, which confirmed good shape memory properties of the PU-SMP. Our findings reveal that even during a single loading-unloading tension cycle, crazes and cracks nucleate on the surface of the PU-SMP specimen, whereas the subsequent temperature-induced shape recovery process carried out at the temperature above Tg enables the healing of micro-cracks. Interestingly, the surface of the specimen after three and five loading-unloading cycles did not exhibit crazes and cracks, although some traces of cracks were visible. The traces disappeared after exposing the material to heating at Tg + 20 °C (65 °C) for 30 min. The crack closure phenomenon during deformation, even without heating over Tg, occurred within three and five subsequent cycles of loading-unloading. Notably, in the case of eight loading-unloading cycles, cracks appeared on the surface of the PU-SMP and were healed only after thermal recovery at the particular temperature over Tg. Upon reaching a critical number of cycles, the proper amount of energy required for crack propagation was attained, resulting in wide-open cracks on the material’s surface. It is worth noting that WAXS analysis did not indicate strong signs of typical highly ordered structures in the PU-SMP specimens in their initial state and after the loading history; however, some orientation after the cyclic deformation was observed.

Keywords:
polyurethane shape memory polymer, glass transition temperature, tensile loading cycles, structure analysis, micro-cracks, healing

Affiliations:
Staszczak M. - IPPT PAN
Urbański L. - IPPT PAN
Gradys A. D. - IPPT PAN
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
Pieczyska E. A. - IPPT PAN
2.  Staszczak M., Urbański L., Cristea M., Ionita D., Pieczyska E.A., Investigation of Shape Memory Polyurethane Properties in Cold Programming Process Towards Its Applications, Polymers, ISSN: 2073-4360, DOI: 10.3390/polym16020219, Vol.16, No.2, pp.219-1-219-20, 2024

Abstract:
Thermoresponsive shape memory polymers (SMPs) with the remarkable ability to remember a temporary shape and recover their original one using temperature have been gaining more and more attention in a wide range of applications. Traditionally, SMPs are investigated using a method named often “hot-programming”, since they are heated above their glass transition temperature (Tg) and after that, reshaped and cooled below Tg to achieve and fix the desired configuration. Upon reheating, these materials return to their original shape. However, the heating of SMPs above their Tg during a thermomechanical cycle to trigger a change in their shape creates a temperature gradient within the material structure and causes significant thermal expansion of the polymer sample resulting in a reduction in its shape recovery property. These phenomena, in turn, limit the application fields of SMPs, in which fast actuation, dimensional stability and low thermal expansion coefficient are crucial. This paper aims at a comprehensive experimental investigation of thermoplastic polyurethane shape memory polymer (PU-SMP) using the cold programming approach, in which the deformation of the SMP into the programmed shape is conducted at temperatures below Tg. The PU-SMP glass transition temperature equals approximately 65 ◦C. Structural, mechanical and thermomechanical characterization was performed, and the results on the identification of functional properties of PU-SMPs in quite a large strain range beyond yield limit were obtained. The average shape fixity ratio of the PU-SMP at room temperature programming was found to be approximately 90%, while the average shape fixity ratio at 45 ◦C (Tg − 20 ◦C) was approximately 97%. Whereas, the average shape recovery ratio was 93% at room temperature programming and it was equal to approximately 90% at 45 ◦C. However, the results obtained using the traditional method, the so-called hot programming at 65 ◦C, indicate a higher shape fixity value of 98%, but a lower shape recovery of 90%. Thus, the obtained results confirmed good shape memory properties of the PU-SMPs at a large strain range at various temperatures. Furthermore, the experiments conducted at both temperatures below Tg demonstrated that cold programming can be successfully applied to PU-SMPs with a relatively high Tg. Knowledge of the PU-SMP shape memory and shape fixity properties, estimated without risk of material degradation, caused by heating above Tg, makes them attractive for various applications, e.g., in electronic components, aircraft or aerospace structures.

Keywords:
polyurethane shape memory polymer, cold programming, thermal expansion, shape fixity, shape recovery

Affiliations:
Staszczak M. - IPPT PAN
Urbański L. - IPPT PAN
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
Ionita D. - other affiliation
Pieczyska E.A. - IPPT PAN
3.  Nabavian Kalat M., Staszczak M., Urbański L., Fernandez C., Vega C., Cristea M., Ionita D., Lantada A., Pieczyska E.A., Investigating a shape memory epoxy resin and its application to engineering shape-morphing devices empowered through kinematic chains and compliant joints, MATERIALS AND DESIGN, ISSN: 0264-1275, DOI: 10.1016/j.matdes.2023.112263, Vol.233, No.112263, pp.1-15, 2023

Abstract:
4D printing is the additive manufacturing (3D printing) of objects that can transform their shape in a controlled and predictable way when subjected to external stimuli. A thermo-responsive shape memory polymer (SMP) is a highly suitable material to 4D print smart devices, due to its actuation function and the capability of recovering its original shape from the deformed one upon heating. This study presents the results of employing an epoxy resin in the additive manufacturing of complex-shaped smart devices with shape-morphing properties using laser stereolithography (SLA). To quantify the shape memory behaviour of the shape memory epoxy (SMEp), we first investigate the thermomechanical properties of the 3D-printed specimens in a tensile testing machine coupled with an environmental thermal chamber. This approach allows us to determine the shape fixity and recovery of SMEp. Next, we propose effective designs of complex-shaped devices, with the aim of promoting shape morphing through micro-actuators and compliant joints acting as active regions in combination with multiplying mechanisms or kinematic chains in each of the devices. We manufacture the complex-shaped prototypes by using SLA directly from the computer-aided designs. The shape memory trials of the 3D-printed prototypes reveal quite precise shape recovery of the devices, illustrating their shape-memory. In fact, the inclusion of micro-actuators and compliant joints within the complex-geometry devices allows for local triggering, deformation and recovery, resulting in a prompt response of the devices to heat. Therefore, innovative designs, along with the suitable smart material and high-quality manufacturing process, lead to 4D printed devices with fast actuation and shape-morphing properties. Overall, this research may contribute to the development of smart materials and 4D printing technology for applications in fields such as biomedical engineering, robotics, transport and aerospace engineering.

Keywords:
Shape memory polymers,Shape memory epoxy,Shape morphing structures,Laser stereolithography,3D and 4D printing

Affiliations:
Nabavian Kalat M. - IPPT PAN
Staszczak M. - IPPT PAN
Urbański L. - IPPT PAN
Fernandez C. - other affiliation
Vega C. - other affiliation
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
Ionita D. - other affiliation
Lantada A. - other affiliation
Pieczyska E.A. - IPPT PAN
4.  Golasiński K., Maj M., Urbański L., Staszczak M., Gradys A.D., Pieczyska E.A., Experimental study of thermomechanical behaviour of Gum Metal during cyclic tensile loadings: the quantitative contribution of IRT and DIC, Quantitative InfraRed Thermography Journal, ISSN: 1768-6733, DOI: 10.1080/17686733.2023.2205762, pp.1-18, 2023

Abstract:
Thermomechanical behaviour of Gum Metal (Ti–23Nb–0.7Ta–2.0Zr–1.2O, at.%) under cyclic tension was experimentally investigated using infrared thermography and digital image correlation. The thermomechanical characteristics of particular stages of the subsequent loading-unloading cycles of Gum Metal were identified, i.e. (I) the linear, elastic loading accompanied by the temperature drop, (II) the nonlinear super-elastic loading related to the temperature growth, (III) the transient stage (at which both the superelastic-like behaviour and the plastic one are present simultaneously) and the temperature starts growing fast, (IV) the plastic deformation with a significant growth of temperature, (V) the superelastic-like unloading accompanied by a fast drop in temperature, (VI) the transient unloading with a slower decrease in temperature and (VII) the elastic unloading, with a slight increase in temperature. Thermoelastic effect in Gum Metal during both loading and unloading was analysed in each tensile cycle. Finally, the evolution of strain and temperature fields just before unloading in each cycle was discussed and a comparison of the fields at selected stages of cycles 12 and 24 was presented. The results of this work enabled us to identify the non-dissipative processes of elastic and superelastic-like deformations as well as the dissipative process of plastic deformation.

Keywords:
Gum Metal,β-Ti alloy,cyclic tension,superelasticity,thermoelastic effect,infrared thermography,digital image correlation

Affiliations:
Golasiński K. - IPPT PAN
Maj M. - IPPT PAN
Urbański L. - IPPT PAN
Staszczak M. - IPPT PAN
Gradys A.D. - IPPT PAN
Pieczyska E.A. - IPPT PAN
5.  Golasiński K., Staszczak M., Pieczyska E.A., Energy Storage and Dissipation in Consecutive Tensile Load-Unload Cycles of Gum Metal, Materials, ISSN: 1996-1944, DOI: 10.3390/ma16093288, Vol.16, No.9, pp.1-17, 2023

Abstract:
Multifunctional β-titanium alloy Gum Metal, characterized by a relatively low elastic modulus, superelastic-like behavior and high strength, was subjected to cyclic tensile loadings. The characteristics of macroscopic scale energy storage and dissipation in the consecutive loading–unloading cycles were studied. Various kinds of energy components related to the alloy deformation process were determined experimentally and analyzed using thermodynamic relations. The values of the entire work needed to deform the alloy Wext, the work used for recoverable deformation Wrec consisting of the elastic deformation energy Wel , the superelastic-like energy Wpt , and the energy of thermoelastic effect Eth , were derived from the Gum Metal stress and temperature vs. strain curves. The irrecoverable mechanical energy Wir expended on plastic deformation, the dissipation energy Q, and finally the stored energy Es were estimated. The stored energy represents a change in the internal energy of the deformed material and is an essential measure of cold-worked state. The Es value turned out to be not large for the Gum Metal, which confirms the alloy low hardening property. The energy components determined for each of the 24 loading cycles enabled us to analyze various stages of the Gum Metal deformation process, including necking and damage.

Keywords:
gum metal, β-Ti alloy, cyclic tension, superelasticity, energy balance, dissipation, stored energy, infrared thermography

Affiliations:
Golasiński K. - IPPT PAN
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
6.  Staszczak M., Gradys A.D., Golasiński K., Pieczyska E.A., Polyurethane Shape Memory Polymer: structure characterization and estimation of energy storage and dissipation during tension process, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.24425/bpasts.2023.147343, Vol.71(6), No.e147343, pp.1-12, 2023

Abstract:
Shape memory polymers (SMP) are new multifunctional materials that are of increasing interest in various functional applications. Among them, polyurethane shape memory polymers (PU-SMP) are particularly attractive due to their combination of shape memory, high strength and biocompatible properties. Developing new applications for PU-SMP requires comprehensive research on their characteristics. This work involved investigating the structure and mechanical behaviour and characterizing the energy storage and dissipation of a thermoplastic PU-SMP with a glass transition temperature (Tg) of 25 °C during tensile loading-unloading. The process of energy storage and dissipation in the PU-SMP was investigated based on the stress-strain curves recorded by a quasi-static testing machine and the temperature changes, accompanying the deformation process, obtained by using a fast and sensitive infrared camera. The results showed that the thermomechanical behaviour of the examined PU-SMP depends significantly on the strain rate. At a higher strain rate, there are higher stress and related temperature changes, which lead to greater energy dissipation. However, the energy storage values estimated during the deformation process turned out to be not significant, indicating that the work supplied to the PU-SMP structure during loading is mainly converted into heat. It should also be noted that the structural investigation revealed no crystalline phase in the investigated PU-SMP

Keywords:
shape memory polymer,infrared camera,thermomechanical couplings,energy storage and dissipation,tension test

Affiliations:
Staszczak M. - IPPT PAN
Gradys A.D. - IPPT PAN
Golasiński K. - other affiliation
Pieczyska E.A. - IPPT PAN
7.  Staszczak M., Nabavian Kalat M., Golasiński K.M., Urbański L., Takeda K., Matsui R., Pieczyska E.A., Characterization of Polyurethane Shape Memory Polymer and Determination of Shape Fixity and Shape Recovery in Subsequent Thermomechanical Cycles, Polymers, ISSN: 2073-4360, DOI: 10.3390/polym14214775, Vol.14, No.4775, pp.1-19, 2022

Abstract:
Multifunctional polyurethane shape memory polymers (PU-SMPs) have been of increasing interest in various applications. Here we report structure characterization, detailed methodology, and obtained results on the identification of functional properties of a thermoset PU-SMP (MP4510) with glass transition temperature of 45 C. The stable, chemically crosslinked network of this thermoset PU-SMP results in excellent shape memory behavior. Moreover, the proximity of the activation temperature range of this smart polymer to room and body temperature enables the PU-SMP to be used in more critical industrial applications, namely fast-response actuators. The thermomechanical behavior of a shape memory polymer determines the engineering applications of the material. Therefore, investigation of the shape memory behavior of this class of commercial PU-SMP is of particular importance. The conducted structural characterization confirms its shape memory properties. The shape fixity and shape recovery properties were determined by a modified experimental approach, considering the polymer’s sensitivity to external conditions, i.e., the temperature and humidity variations. Three thermomechanical cycles were considered and the methodology used is described in detail. The obtained shape fixity ratio of the PU-SMP was approximately 98% and did not change significantly in the subsequent cycles of the thermomechanical loading due to the stability of chemical crosslinks in the thermoset materials structure. The shape recovery was found to be approximately 90% in the first cycle and reached a value higher than 99% in the third cycle. The results confirm the effect of the thermomechanical training on the improvement of the PU-SMP shape recovery after the first thermomechanical cycle as well as the effect of thermoset material stability on the repeatability of the shape memory parameters quantities.

Keywords:
polyurethane shape memory polymer, thermomechanical loading program, shape fixity, shape recovery

Affiliations:
Staszczak M. - IPPT PAN
Nabavian Kalat M. - IPPT PAN
Golasiński K.M. - IPPT PAN
Urbański L. - IPPT PAN
Takeda K. - Aichi Institute of Technology (JP)
Matsui R. - Aichi Institute of Technology (JP)
Pieczyska E.A. - IPPT PAN
8.  Golasiński K.M., Pieczyska E.A., Maj M., Staszczak M., Świec P., Furuta T., Kuramoto S., Investigation of strain rate sensitivity of gum metal under tension using digital image correlation, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1007/s43452-020-00055-9, Vol.20, No.2, pp.53-1-14, 2020

Abstract:
Mechanical behavior of a multifunctional titanium alloy Gum Metal was investigated by conducting tensile tests at various strain rates and applying digital image correlation (DIC) technique. Stress–strain curves confirmed low Young's modulus and high strength of the alloy. The determined values of yield strength had a tendency to increase, whereas the elongation to the specimen rupture tended to decrease with increasing strain rate. True stress versus strain curves were analyzed using selected lengths of virtual extensometer (VE) placed in the strain localization area. When the initial length of the VE was the same as the gauge length, work hardening was observed macroscopically at lower strain rates, and a softening was seen at higher strain rates. However, the softening effect was not observed at the shorter VE lengths. Evolution of the Hencky strain and rate of deformation tensor component fields were analyzed for various strain rates at selected stages of Gum Metal loading. The DIC analysis demonstrated that for lower strain rates the deformation is macroscopically uniform up to the higher average Hencky strains, whereas for higher strain rates the strain localization occurs at the lower average Hencky strains of the deformation process and takes place in the smaller area. It was also found that for all strain rates applied, the maximal values of Hencky strain immediately before rupture of Gum Metal samples were similar for each of the applied strain rates, and the maximal local values of deformation rate were two orders higher when compared to applied average strain rate values.

Keywords:
titanium alloy, gum metal, strain rate sensitivity, strain localization, digital image correlation, full-field deformation analysis

Affiliations:
Golasiński K.M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Staszczak M. - IPPT PAN
Świec P. - other affiliation
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
9.  Golasiński K.M., Pieczyska E.A., Maj M., Mackiewicz S., Staszczak M., Kowalewski Z.L., Urbański L., Zubko M., Takesue N., Anisotropy of gum metal analysed by ultrasonic measurement and digital image correlation, MATERIALS SCIENCE AND TECHNOLOGY, ISSN: 0267-0836, DOI: 10.1080/02670836.2019.1629539, Vol.36, No.9, pp.996-1002, 2020

Abstract:
The mechanical anisotropy of a multifunctional titanium alloy, Gum Metal, is investigated in this paper. The structural characterisation showed a strong <110> texture for Gum Metal, that is a result of the cold-swaging process applied during its manufacture. Gum Metal was treated as a transversally isotropic solid because of this texture. A significant difference from Young's moduli of the alloy was detected from the ultrasonic measurement of parallel and perpendicular directions to the alloy swaging direction. Samples of Gum Metal cubes were compressed in two different orientations. During the deformation process, two perpendicular walls of each sample were monitored by two visible range cameras for further two-dimensional digital image correlation analysis, this confirmed a strong plastic anisotropy in Gum Metal.

Keywords:
gum metal, compression, mechanical anisotropy, digital image correlation, ultrasonic measurement, texture, titanium alloy, full-field deformation measurement

Affiliations:
Golasiński K.M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Mackiewicz S. - IPPT PAN
Staszczak M. - IPPT PAN
Kowalewski Z.L. - IPPT PAN
Urbański L. - IPPT PAN
Zubko M. - other affiliation
Takesue N. - Fukuoka University (JP)
10.  Pieczyska E.A., Golasiński K.M., Maj M., Staszczak M., Kowalewski Z.L., Furuta T., Kuramoto S., Yielding and strain localization effects in gum metal - a unique Ti alloy - investigated by digital image correlation and infrared thermography, Materials Today: Proceedings, ISSN: 2214-7853, DOI: 10.1016/j.matpr.2019.03.119, Vol.12, pp.235-238, 2019

Abstract:
The research concerns investigation of yielding and developing of the strain localization in new β-Ti alloy characterized by unique elastic-plastic properties, named Gum Metal. The alloy was subjected to tension on testing machine at three various strain rates up to rupture. Digital image correlation and infrared thermography were applied to analyze the experimental results. Strain distributions were determined on the basis of digital image correlation algorithm. The related temperature variations were found in contactless manner using infrared thermography. Mechanical and the corresponding thermal data were used to study the Gum Metal large nonlinear reversible deformation and localization effects.

Keywords:
gum metal, tension, large nonlinear elastic deformation, thermomechanical couplings, temperature change, digital image correlation

Affiliations:
Pieczyska E.A. - IPPT PAN
Golasiński K.M. - IPPT PAN
Maj M. - IPPT PAN
Staszczak M. - IPPT PAN
Kowalewski Z.L. - IPPT PAN
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
11.  Pieczyska E.A., Maj M., Golasiński K.M., Staszczak M., Furuta T., Kuramoto S., Thermomechanical Studies of Yielding and Strain Localization Phenomena of Gum Metal under Tension, Materials, ISSN: 1996-1944, DOI: 10.3390/ma11040567, Vol.11, No.567, pp.1-13, 2018

Abstract:
This paper presents results of investigation of multifunctional beta-Ti alloy Gum Metal subjected to tension at various strain rates. Digital image correlation was used to determine strain distributions and stress-strain curves, while infrared camera allowed for us to obtain the related temperature characteristics of the specimen during deformation. The mechanical curves completed by the temperature changes were applied to analyze the subsequent stages of the alloy loading. Elastic limit, recoverable strain, and development of the strain localization were studied. It was found that the maximal drop in temperature, which corresponds to the yield limit of solid materials, was referred to a significantly lower strain value in the case of Gum Metal in contrast to its large recoverable strain. The temperature increase proves a dissipative character of the process and is related to presence of w and a” phases induced during the alloy fabrication and their exothermic phase transformations activated under loading. During plastic deformation, both the strain and temperature distributions demonstrate that strain localization for higher strain rates starts nucleating just after the yield limit leading to specimen necking and rupture. Macroscopically, it is exhibited as softening of the stress-strain curve in contrast to the strain hardening observed at lower strain rates.

Keywords:
gum metal, yield limit, thermomechanical coupling, infrared thermography, digital image correlation, strain localization

Affiliations:
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Golasiński K.M. - IPPT PAN
Staszczak M. - IPPT PAN
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
12.  Pieczyska E.A., Staszczak M., Kowalczyk-Gajewska K., Maj M., Golasiński K.M., Golba S., Tobushi H., Hayashi S., Experimental and numerical investigation of yielding phenomena in a shape memory polymer subjected to cyclic tension at various strain rates, POLYMER TESTING, ISSN: 0142-9418, DOI: 10.1016/j.polymertesting.2017.04.014, Vol.60, pp.333-342, 2017

Abstract:
This paper presents experimental and numerical results of a polyurethane shape memory polymer (SMP) subjected to cyclic tensile loading. The goal was to investigate the polymer yielding phenomena based on the effects of thermomechanical coupling. Mechanical characteristics were obtained with a testing machine, whereas the SMP temperature accompanying its deformation process was simultaneously measured in a contactless manner with an infrared camera. The SMP glass transition temperature was approximately 45oC; therefore, when tested at room temperature, the polymer is rigid and behaves as solid material. The stress and related temperature changes at various strain rates showed how the SMP yield limit evolved in subsequent loading-unloading cycles under various strain rates. A two-phase model of the SMP was applied to describe its mechanical response in cyclic tension. The 3D Finite Element model of a tested specimen was used in simulations. Good agreement between the model predictions and experimental results was observed for the first tension cycle.

Keywords:
Shape memory polymer, Tension cyclic loading, Thermomechanical coupling, Yield limit, Thermoelastic effect, Constitutive model

Affiliations:
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Maj M. - IPPT PAN
Golasiński K.M. - IPPT PAN
Golba S. - University of Silesia (PL)
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
13.  Golasiński K.M., Pieczyska E.A., Staszczak M., Maj M., Furuta T., Kuramoto S., Infrared thermography applied for experimental investigation of thermomechanical couplings in Gum Metal, Quantitative InfraRed Thermography Journal, ISSN: 1768-6733, DOI: 10.1080/17686733.2017.1284295, Vol.14, No.2, pp.1-8, 2017

Abstract:
Results of initial investigation of thermomechanical couplings in innovative β-Ti alloy called Gum Metal subjected to tension are presented. The experimental set-up, consisting of testing machine and infrared camera, enabled to obtain stress–strain curves with high accuracy and correlate them to estimated temperature changes of the specimen during the deformation process. Both ultra-low elastic modulus and high strength of Gum Metal were confirmed. The infrared measurements determined average and maximal temperature changes accompanying the alloy deformation process, allowed to estimate thermoelastic effect, which is related to the alloy yield point. The temperature distributions on the specimen surface served to analyse strain localization effects leading to the necking and rupture.

Keywords:
gum metal, thermomechanical coupling, nonlinear elasticity, yield point, infrared camera

Affiliations:
Golasiński K.M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
14.  Pieczyska E.A., Staszczak M., Maj M., Kowalczyk-Gajewska K., Golasiński K.M., Cristea M., Tobushi H., Hayashi S., Investigation of thermomechanical couplings, strain localization and shape memory properties in a shape memory polymer subjected to loading at various strain rates, SMART MATERIALS AND STRUCTURES, ISSN: 0964-1726, DOI: 10.1088/0964-1726/25/8/085002, Vol.25, No.8, pp.085002-1-15, 2016

Abstract:
This paper presents experimental and modeling results of the effects of thermomechanical couplings occurring in a polyurethane shape memory polymer (SMP) subjected to tension at various strain rates within large strains. The SMP mechanical curves, recorded using a testing machine, and the related temperature changes, measured in a contactless manner using an IR camera, were used to investigate the polymer deformation process at various loading stages. The effects of thermomechanical couplings allowed the determination of the material yield point in the initial loading stage, the investigation of nucleation and development of the strain localization at larger strains and the estimation of the effects of thermoelastic behavior during the unloading process. The obtained stress–strain and thermal characteristics, the results of the dynamic mechanical analysis and estimated values of the shape fixity and shape recovery parameters confirmed that the shape memory polymer (T g = 45°C) is characterized by good mechanical and shape memory properties, as well as high sensitivity to the strain rate. The mechanical response of the SMP subjected to tension was simulated using the finite element method and applying the large strain, two-phase model. Strain localization observed in the experiment was well reproduced in simulations and the temperature spots were correlated with the accumulated viscoplastic deformation of the SMP glassy phase.

Keywords:
shape memory polymer, thermomechanical coupling, infrared camera, tension test, strain rate, strain localization, constitutive model

Affiliations:
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Golasiński K.M. - IPPT PAN
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
15.  Staszczak M., Pieczyska E.A., Maj M., Kukla D., Tobushi H., Infrared thermographic analysis of shape memory polymer during cyclic loading, MEASUREMENT SCIENCE AND TECHNOLOGY, ISSN: 0957-0233, DOI: 10.1088/0957-0233/27/12/124007, Vol.27, No.12, pp.124007-1-6, 2016

Abstract:
In this paper we present the effects of thermomechanical couplings occurring in polyurethane shape memory polymer subjected to cyclic tensile loadings conducted at various strain rates. Stress–strain characteristics were elaborated using a quasistatic testing machine, whereas the specimen temperature changes accompanying the deformation process were obtained with an infrared camera. We demonstrate a tight correlation between the mechanical and thermal results within the initial loading stage. The polymer thermomechanical behaviour in four subsequent loading-unloading cycles and the influence of the strain rate on the stress and the related temperature changes were also examined. In the range of elastic deformation the specimen temperature drops below the initial level due to thermoelastic effect whereas at the higher strains the temperature always increased, due to the dissipative deformation mechanisms. The difference in the characteristics of the specimen temperature has been applied to determine a limit of the polymer reversible deformation and analyzed for various strain rates. It was shown that at the higher strain rates higher values of the stress and temperature changes are obtained, which are related to higher values of the polymer yield points. During the cyclic loading a significant difference between the first and the second cycle was observed. The subsequent loading-unloading cycles demonstrated similar sharply shaped stress and temperature profiles and gradually decrease in values.

Keywords:
thermomechanical couplings, infrared camera, shape memory polymer, tension, strain rate, thermoelastic effect, yield point

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Kukla D. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
16.  Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Staszczak M., Gradys A., Majewski M., Cristea M., Tobushi H., Hayashi S., Thermomechanical properties of polyurethane shape memory polymer–experiment and modelling, SMART MATERIALS AND STRUCTURES, ISSN: 0964-1726, DOI: 10.1088/0964-1726/24/4/045043, Vol.24, pp.045043-1-16, 2015

Abstract:
In this paper extensive research on the polyurethane shape memory polymer (PU-SMP) is reported, including its structure analysis, our experimental investigation of its thermomechanical properties and its modelling. The influence of the effects of thermomechanical couplings on the SMP behaviour during tension at room temperature is studied using a fast and sensitive infrared camera. It is shown that the thermomechanical behaviour of the SMP significantly depends on the strain rate: at a higher strain rate higher stress and temperature values are obtained. This indicates that an increase of the strain rate leads to activation of different deformation mechanisms at the micro-scale, along with reorientation and alignment of the molecular chains. Furthermore, influence of temperature on the SMP's mechanical behaviour is studied. It is observed during the loading in a thermal chamber that at the temperature 20°C below the glass transition temperature (Tg) the PU-SMP strengthens about six times compared to the material above Tg but does not exhibit the shape recovery. A finite-strain constitutive model is formulated, where the SMP is described as a two-phase material composed of a hyperelastic rubbery phase and elastic-viscoplastic glassy phase. The volume content of phases is governed by the current temperature. Finally, model predictions are compared with the experimental results.

Keywords:
shape memory polyurethane, thermomechanical couplings, infrared camera, temperature change, dynamic mechanical analysis, strain rate, constitutive model

Affiliations:
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Staszczak M. - IPPT PAN
Gradys A. - IPPT PAN
Majewski M. - IPPT PAN
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
17.  Pieczyska E.A., Staszczak M., Maj M., Tobushi H., Hayashi S., Investigation of thermal effects accompanying tensile deformation of Shape Memory Polymer PU-SMP, Measurement Automation Monitoring, ISSN: 0032-4140, Vol.61, No.6, pp.203-205, 2015

Abstract:
Experimental results of effects of thermomechanical couplings occurring in shape memory polymer subjected to tension are presented. Stress-strain curves were recorded by testing machine, while their related temperature changes were measured with infrared camera. The mechanical and thermal characteristics were used to investigate the polymer properties. Three various stages were distinguished during the deformation process. The first, elastic, is accompanied by a drop in the specimen temperature; the second, plastic, is associated with change of the material structure and the temperature increase; the third stage, related to the specimen rupture and damage mechanisms, is accompanied by the significant increase in temperature.

Keywords:
shape memory polymer, tension, thermomechanical coupling, temperature change, infrared camera

Affiliations:
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
18.  Staszczak M., Pieczyska E.A., Maj M., Urbański L., Odriozola I., Martin R., Thermomechanical Properties of Vulcanized Rubber investigated by Testing Machine and Infrared Camera, Measurement Automation Monitoring, ISSN: 0032-4140, Vol.61, No.6, pp.206-209, 2015

Abstract:
Experimental results of effects of thermomechanical couplings occurring both in natural vulcanized rubber and rubber with self-healing polyurethane subjected to tension at different strain rates are presented. Mechanical characteristics were recorded by testing machine, while the sample temperature changes accompanying the deformation process was measured by infrared camera. The goal was to investigate influence of self-healing polyurethane on the rubber mechanical and thermomechanical properties. It was found that the introduction of the self-healing polyurethane ensures the higher elasticity and the lower tensile strength of the rubber. It was also confirmed that the material is very sensitive to the strain rate; the higher the strain rate, the higher the values of the stress and temperature increases have been obtained.

Keywords:
vulcanized rubber, self-healing polyurethane, tension test, thermomechanical couplings, temperature changes, infrared camera

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Urbański L. - IPPT PAN
Odriozola I. - IK4-CIDETEC (ES)
Martin R. - IK4-CIDETEC (ES)
19.  Dunić V., Pieczyska E.A., Tobushi H., Staszczak M., Slavković R., Experimental and numerical thermo-mechanical analysis of shape memory alloy subjected to tension with various stress and strain rates, SMART MATERIALS AND STRUCTURES, ISSN: 0964-1726, DOI: 10.1088/0964-1726/23/5/055026, Vol.23, pp.055026-1-11, 2014

Abstract:
TiNi shape memory alloy (SMA) is experimentally and numerically investigated in tension tests under different loading rates. The thermomechanical behaviour of the SMA, related to the stress-induced martensitic transformation (SIMT) noticed during the experimental tests, is analysed and the observations are considered for numerical analysis. Initiation, development and saturation of the SIMT are monitored by a fast and sensitive infrared camera. The estimated temperature changes of the SMA sample, related to the exothermic martensitic forward and endothermic reverse transformation, have been analysed with the focus on the rate-dependent response and on the influence of the heat transfer on the mechanical behaviour. The effectively modified constitutive model, proposed by Lagoudas, is implemented in structural PAK finite element method (FEM) software and is thermomechanically coupled with the heat transfer FEM software in a partitioned approach. The experimental results are quantitatively and qualitatively reproduced by the numerical FEM model, which verifies the efficiency and accuracy of the proposed investigation method.

Keywords:
shape memory alloy, stressinduced martensitic transformation, modelling, TiNi, tension, infrared camera, temperature changes

Affiliations:
Dunić V. - University of Kragujevac (XS)
Pieczyska E.A. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Staszczak M. - IPPT PAN
Slavković R. - University of Kragujevac (XS)
20.  Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Staszczak M., Urbański L., Tobushi H., Hayashi S., Cristea M., Mechanical and Infrared Thermography Analysis of Shape Memory Polyurethane, Journal of Materials Engineering and Performance, ISSN: 1059-9495, DOI: 10.1007/s11665-014-0963-2, Vol.23, No.7, pp.2553-2560, 2014

Abstract:
Multifunctional new material—polyurethane shape memory polymer (PU-SMP)—was subjected to tension carried out at room temperature at various strain rates. The influence of effects of thermomechanical couplings on the SMP mechanical properties was studied, based on the sample temperature changes, measured by a fast and sensitive infrared camera. It was found that the polymer deformation process strongly depends on the strain rate applied. The initial reversible strain is accompanied by a small drop in temperature, called thermoelastic effect. Its maximal value is related to the SMP yield point and increases upon increase of the strain rate. At higher strains, the stress and temperature significantly increase, caused by reorientation of the polymer molecular chains, followed by the stress drop and its subsequent increase accompanying the sample rupture. The higher strain rate, the higher stress, and temperature changes were obtained, since the deformation process was more dynamic and has occurred in almost adiabatic conditions. The constitutive model of SMP valid in finite strain regime was developed. In the proposed approach, SMP is described as a two-phase material composed of hyperelastic rubbery phase and elastic-viscoplastic glassy phase, while the volume content of phases is specified by the current temperature.

Keywords:
constitutive model, dynamic mechanical analysis, shape memory polyurethane, strain rate, temperature change, thermomechanical couplings

Affiliations:
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Staszczak M. - IPPT PAN
Urbański L. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
21.  Pieczyska E.A., Staszczak M., Dunić V., Slavković R., Tobushi H., Takeda K., Development of Stress-Induced Martensitic Transformation in TiNi Shape Memory Alloy, Journal of Materials Engineering and Performance, ISSN: 1059-9495, DOI: 10.1007/s11665-014-0959-y, Vol.23, No.7, pp.2505-2514, 2014

Abstract:
TiNi shape memory alloy (SMA) was subjected to tension at strain-controlled test on quasistatic testing machine. The nucleation, development, and saturation of the stress-induced martensitic transformation were investigated, taking into account the obtained dependency of mechanical parameters and the specimen temperature changes measured by an infrared camera (IR). Three kinds of data obtained by the IR system were analyzed: the temperature distribution on the SMA sample surface, the temperature changes derived as average from the chosen sample area, and the temperature profiles obtained along the sample length. The temperature distribution shows nucleation of the transformation process and a creation of the transformation bands. The average temperature reflects the effects of thermomechanical coupling, accompanying exothermic martensitic forward and endothermic reverse transformation. The temperature profiles revealed the temperature difference between the band and the rest of the sample. The experimental results were supported with finite element method numerical analysis (FEM). The FEM software components for structural and heat transfer problems, coupled in partitioned approach, were used for thermomechanical analysis.

Keywords:
finite element modeling, infrared camera, material testing, martensitic transformation, TiNi shape memory alloy, tension, thermomechanical couplings

Affiliations:
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Dunić V. - University of Kragujevac (XS)
Slavković R. - University of Kragujevac (XS)
Tobushi H. - Aichi Institute of Technology (JP)
Takeda K. - Aichi Institute of Technology (JP)
22.  Pieczyska E.A., Kowalczyk-Gajewska K., Maj M., Staszczak M., Tobushi H., Thermomechanical investigation of TiNi shape memory alloy and PU shape memory polymer subjected to cyclic loading, Procedia Engineering, ISSN: 1877-7058, DOI: 10.1016/j.proeng.2014.06.264, Vol.74, pp.287-292, 2014

Abstract:
In applications to sensors, actuators, guide wires, special grips for handicapped people, a shape memory alloy (SMA) or shape memory polymer (SMP) are used as working elements that perform cyclic motions. In order to evaluate the reliability of the shape memory materials (SMM), cycling and fatigue deformation properties are investigated. Since the SMM are very sensitive to temperature, not only mechanical properties but also their related temperature changes accompanying the deformation process should be taken into account. The presented paper embraces experimental investigation of effects of thermomechanical couplings occurring in shape memory alloy and shape memory polymer subjected to various kinds of cycling loading. The deformation was carried out on MTS 858 Testing machine. The strain was measured by a mechanical extensometer, so the stress-strain characteristics were elaborated with high accuracy. Furthermore, a fast and sensitive FLIR Co Phoenix infrared (IR) measurement system was used in order to record infrared radiation from the sample surface. It enables obtaining temperature distribution of the sample as a function of the deformation parameters. For each strain cycle, an increase in temperature during the loading and the temperature decrease during the unloading processes was observed. It was found that the temperature increment recorded during the cyclic deformation depends on the strain rate, the kind of the material and the test conditions. The higher the strain rate the higher the stress and temperature changes were obtained, since the deformation process was more dynamic and has occurred in almost adiabatic conditions. It was shown that various deformation mechanisms are active during various loading stages.

Keywords:
shape memory alloy, shape memory polymer, cyclic deformation, thermomechanical coupling, infrared camera

Affiliations:
Pieczyska E.A. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Maj M. - IPPT PAN
Staszczak M. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
23.  Staszczak M., Pieczyska E.A., Maj M., Urbański L., Tobushi H., Hayashi S., Właściwości mechaniczne oraz zmiany temperatury polimeru z pamięcią kształtu w procesie rozciągania, POMIARY AUTOMATYKA KONTROLA, ISSN: 0032-4140, Vol.59, No.9, pp.1002-1005, 2013

Abstract:
This paper presents experimental evaluation of a new polyurethane shape memory polymer (PU-SMP) produced by SMP Technologies Inc. It discusses mechanical characteristics and temperature changes of the SMP specimens subjected to tension test performed at room temperature with various strain rates. Basing on the mechanical data and the relevant temperature changes, we have studied the thermomechanical properties of the PU-SMP and influence of the strain rate on the strain localization behavior. Finally, we have identified the material parameters for the one-dimensional rheological model of the SMP.

Keywords:
shape memory polyurethane, tension test, dynamic mechanical analysis, infrared camera, temperature change, thermomechanical properties, rheological model

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Urbański L. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)

Conference papers
1.  Pieczyska E.A., Golasiński K., Maj M., Staszczak M., Gum metal thermomechanical properties in initial stage of the loading and deformation, DAS37, 37th Danubia Adria Symposium on Advances in Experimental Mechanics, 2021-09-21/09-24, Linz (AT), pp.27-28, 2021
2.  Pieczyska E.A., Golasiński K.M., Staszczak M., Maj M., Furuta T., Kuramoto S., INFRARED THERMOGRAPHY AND DIC USED TO INVESTIGATE GUM METAL LOCALIZATION EFFECTS, IRF2018, 6th International Conference Integrity-Reliability-Failure, 2018-07-22/07-26, Lizbona (PT), No.7199, pp.825-826, 2018

Abstract:
This paper presents an investigation of strain localization phenomena during tension of a β-Ti alloy Gum Metal that can deform reversibly to large strains (around 2%). Digital image correlation (DIC), with the especially developed PAN algorithm at IPPT, and infrared thermography were used to determine strain and the related temperature distributions with high accuracy. The analysis of strain and temperature distributions showed that the increase in the strain rate affects both the onset and development of the strain localization process.

Keywords:
infrared thermography, thermomechanical behavior, gum metal

Affiliations:
Pieczyska E.A. - IPPT PAN
Golasiński K.M. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
3.  Golasiński K.M., Pieczyska E.A., Maj M., Staszczak M., Kuramoto S., Gum Metal under cyclic tension inspected by a fast and sensitive infrared camera, QIRT 2018, 14th Quantitative InfraRed Thermography Conference, 2018-06-25/06-29, Berlin (DE), pp.1-6, 2018

Abstract:
This work presents results of experimental investigation of recoverable deformation of a β-Ti alloy Gum Metal inspected by infrared (IR) thermography. To this end, a flat specimen of Gum Metal was subjected to cyclic tension with an increasing strain on a testing machine and was simultaneously monitored by a fast and sensitive IR camera. The IR measurements determined an average temperature accompanying the alloy deformation process for subsequent tension cycles and allowed to estimate thermoelastic effect, which is related to the alloy yield point. Thermomechanical couplings accompanying the loading-unloading cycles were analyzed for estimating the range of reversible deformation from mechanical and thermal perspectives as well as discussed in the view of Lord Kelvin's formula.

Affiliations:
Golasiński K.M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Staszczak M. - IPPT PAN
Kuramoto S. - Ibaraki University Japan (JP)
4.  Golasiński K.M., Pieczyska E.A., Staszczak M., Maj M., Furuta T., Kuramoto S., Infrared thermography applied for experimental investigation of thermomechanical couplings in Gum Metal, QIRT 2016, XIII International Quantitative InfraRed Thermography Conference, 2016-06-04/06-08, Gdańsk (PL), DOI: 10.21611/qirt.2016.038, pp.291-296, 2016

Abstract:
Results of investigation of thermomechanical couplings in innovative β-Ti alloy (Gum Metal) subjected to tension are presented. The experimental set-up, consisting of testing machine and infrared camera, enabled to obtain stress-strain curves with high accuracy and correlate them to estimated temperature changes of the sample during the deformation process. Both ultra-low elastic modulus and high strength of Gum Metal were confirmed. The infrared measurements determined average and maximal temperature changes accompanying the alloy deformation process, allowed to estimate thermoelastic effect, which is related to the alloy yield point. The temperature distributions on the sample surface served to analyze localization effects leading to the sample necking and rupture.

Keywords:
Gum metal, nonlinear elasticity, thermomechanical couplings

Affiliations:
Golasiński K.M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
5.  Pieczyska E.A., Staszczak M., Maj M., Kowalczyk-Gajewska K., Cristea M., Tobushi H., Hayashi S., Thermomechanical analysis of shape memory polyurethane PU-SMP, 6th International Conference on Mechanics and Materials in Design, 2015-07-26/07-30, Ponta Delgada (PT), pp.783-786, 2015

Abstract:
Experimental results of effects of thermomechanical couplings occurring in polyurethane shape memory polymer (PU-SMP) during tension at different strain rates are presented. Stress-strain curves were recorded by MTS 858 testing machine. The temperature changes were estimated by using a fast and sensitive infrared camera (Phoenix FLIR IR System). The stress and temperature vs. strain characteristics obtained during the tension enable to investigate the SMP deformation process and distinguish 3 different stages: the first, accompanied by a drop in temperature called thermoelastic effect, related to a limit of the material reversible deformation, the second plastic stage, associated with change of the material structure and significant increase in temperature, and the third - related to the mechanisms of damage - a breaking of the polymer chains, leading to the specimen rupture.

Keywords:
shape memory polymer, thermomechanical coupling, tension, infrared camera

Affiliations:
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
6.  Staszczak M., Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Kukla D., Tobushi H., Hayashi S., Infrared thermography analysis of thermomechanical shape memory polymer behavior – initial loading stage, AITA, 13th International Workshop on Advanced Infrared Technology and Applications, 2015-09-29/10-02, Pisa (IT), pp.115-118, 2015

Abstract:
Experimental results of effects of thermomechanical couplings occurring in polyurethane shape memory polymer (PU-SMP) subjected to cyclic loading at various strain rates are presented. Stress-strain characteristics were recorded by the testing machine, whereas the specimen temperature changes were measured by a fast and sensitive infrared camera. The influence of strain rate on the polymer thermomechanical behaviour was studied. It was found that the SMP is very sensitive to the strain rate. The higher the strain rate, the higher the values of the stress and temperature changes were obtained. In the initial stage of deformation a drop in temperature called thermoelastic effect, determining a limit of the material reversible deformation, was investigated.

Keywords:
thermomechanical couplings, polyurethane shape memory polymer, cyclic loading, various strain rates, sensitive infrared camera, thermoelastic effect, thermoelastic effect, reversible deformation

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Kukla D. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
7.  Staszczak M., Pieczyska E.A., Maj M., Urbański L., Odriozola I., Martin R., Właściwości termomechaniczne gumy wulkanizowanej badane za pomocą maszyny wytrzymałościowej oraz kamery termowizyjnej, 11th Conference on Thermography and Thermometry in Infrared, 2015-09-22/09-24, Ustroń (PL), pp.66-67, 2015

Abstract:
Praca przedstawia wyniki doświadczalnych badań efektów sprzężeń termomechanicznych w naturalnej, wulkanizowanej gumie z różną zawartością poliuretanu o właściwościach samo-naprawiania, tzw. „self-healing” podczas obciążania z różnymi prędkościami deformacji. Próbki rozciągano na maszynie wytrzymałościowej wysokiej klasy, co pozwoliło otrzymać charakterystyki mechaniczne z wysoką dokładnością, a szybka i czuła kamera termowizyjna pozwoliła otrzymać w sposób bezstykowy zmiany temperatury próbek związane z ich odkształcaniem. Stwierdzono, że im więcej dodatku poliuretanu, tym wyższa sprężystość gumy oraz niższa jej wytrzymałość. Ponadto, otrzymane wyniki potwierdziły wysoką wrażliwość materiału na prędkość deformacji: im wyższa prędkość, tym wyższe wartości naprężenia oraz zmian temperatury.

Keywords:
efekty sprzężeń termomechanicznych, wulkanizowana guma, poliuretan self-healing, prędkość deformacji, maszyna wytrzymałościowa, kamera termowizyjna

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Urbański L. - IPPT PAN
Odriozola I. - IK4-CIDETEC (ES)
Martin R. - IK4-CIDETEC (ES)
8.  Pieczyska E.A., Staszczak M., Maj M., Tobushi H., Hayashi S., Thermal effects accompanying tensile deformation of shape memory polymer PU-SMP, 11th Conference on Thermography and Thermometry in Infrared, 2015-09-22/09-24, Ustroń (PL), pp.60-65, 2015

Abstract:
In the paper experimental results of the effects of thermomechanical couplings occurring in polyurethane shape memory polymer (PU-SMP), produced by SMP Techno Tokyo, subjected to tension with various strain rates are presented. Stress-strain curves were recorded by MTS 858 testing machine with a high accuracy, while using a fast and sensitive infrared camera (Phoenix FLIR IR System) enables to obtain the temperature distribution on the specimen surface, estimate the average temperature and investigate effects of the strain localization during the deformation process. The higher the strain rate the higher the changes in the stress and in temperature are observed, since the deformation mechanisms occur in more dynamic manner and the loading process is closer to adiabatic conditions.

Keywords:
shape memory polymer, thermomechanical couplings, tension, infrared camera, thermoelastic effect, yield point, temperature distribution, strain localization, strain rate, adiabatic conditions

Affiliations:
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
9.  Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Staszczak M., Tobushi H., Hayashi S., Thermomechanical properties of shape memory alloys and polymers studied by advanced infrared techniques, PACAM, 14th Pan-American Congress of Applied Mechanics, 2014-03-24/03-28, Santiago (CL), pp.1-6, 2014

Abstract:
The paper presents experimental evaluation and modelling of effects of thermomechanical couplings in shape memory alloy (SMA) and shape memory polymer (SMP). TiNi SMA and polyurethane PU-SMP are subjected to tension on MTS Testing machine. Fast infrared camera (IR) Phoenix FLIR System enable obtaining temperature distribution and average temperature changes of the specimens during the deformation process. Mechanical and infrared characteristics recorded during the SMA loading show that after initial, macroscopically homogeneous deformation a localized transformation develops, accompanied by significant temperature changes. Inclined bands of higher temperature accompanying exothermic forward transformation are recorded during the loading, whereas bands of lower temperature related to endothermic reverse transformation are observed during the unloading process. The infrared imaging and average temperature of the SMA sample compared to their mechanical characteristics allow to investigate the current stage of the stress-induced transformation process. A decrease of the specimen temperature reveals the saturation stage of the transformation. Both mechanical and thermal effects significantly depend on the strain rate; the higher the strain rate, the higher the temperature and stress are obtained. Similar experimental methodology is applied to investigate effects of thermomechanical couplings in shape memory polyurethane subjected to tension at various strain rates. Constitutive model valid in finite strain regime is proposed, where the SMP is described as a two-phase material composed of hyperelastic rubbery phase and elastic-viscoplastic glassy phase, while the volume content of phases is specified by the current temperature. Experimental results and modelling show that the SMP deformation process strongly depends on the strain rate, much stronger than for metals and alloys. At higher strain rate higher stress and temperature changes are obtained, since the deformation process is more dynamic and occurs in almost adiabatic conditions. It is shown that during the SMP loading process various deformation mechanisms are active at various strain rates.

Keywords:
shape memory alloy, transformation bands, infrared camera, constitutive model, shape memory polymers, elastic modulus, yield stress, glass transition temperature, shape fixity, shape recovery

Affiliations:
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Staszczak M. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
10.  Staszczak M., Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Cristea M., Tobushi H., Hayashi S., Mechanical and infrared thermography analysis of shape memory polymer - focus on thermoelastic effect, QIRT 2014, 12th International Conference on Quantitative Infrared Thermography, 2014-07-07/07-11, Bordeaux (FR), pp.183-1-9, 2014

Abstract:
Experimental results of effects of thermomechanical couplings occurring in polyurethane shape memory polymer (PU-SMP) subjected to cyclic loading at, are presented. Stress-strain characteristics were recorded by the testing machine, whereas the specimen temperature changes were measured by a fast and sensitive infrared camera. The influence of strain rate on the polymer thermomechanical behaviour is studied. It was found that PU-SMP is very sensitive to the strain rate. The higher the strain rate, the higher the values of stress and temperature changes were obtained. In the initial stage of deformation a drop in temperature called thermoelastic effect was recorded determining a limit of the material reversible deformation.

Keywords:
thermomechanical couplings, polyurethane shape memory polymer, cyclic loading, different strain rates, infrared camera, thermoelastic effect

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)

Conference abstracts
1.  Nabavian Kalat M., Staszczak M., Urbański L., Lantada A.D., Pieczyska E., Shape Memory Epoxy Resin for Shape-Morphing Additive Manufacturing, DAS 2023, 39th Danubia-Adria Symposium on Advances in Experimental Mechanics, 2023-09-26/09-29, Siofok (HU), pp.46-47, 2023
2.  Pieczyska E.A., Staszczak M., Janiszewski J., Sienkiewicz J., Investigation of thermomechanical properties during biaxial loading of βTi alloy named Gum Metal that combines high strength to high elastic properties, 67th Course: Progress in Photoacoustic & Photothermal Phenomena, Focus on Biomedical, Nanoscale, NDE, Gas Sensing and Thermopysical Phenomena and Technologies, 2023-09-24/10-01, Erice (IT), No.D3, pp.1-1, 2023
3.  Staszczak M., Urbański L., Gradys A., Pieczyska E., Structural characterization and investigation of shape memory performance of thermoset polyurethane shape memory polymer, ECNP 2023 , 11th ECNP International Conference on Nanostructured Polymers and Nanocomposites, 2023-08-28/08-31, Łódź (PL), No.P32, pp.93-93, 2023
4.  Pieczyska E.A., Kowalczyk-Gajewska K., Staszczak M., Golasiński K., Judyta Sienkiewicz J., Janiszewski J., MECHANICAL BEHAVIOR AND THE RELATED TEMPERATURE CHANGES INVESTIGATED FOR β Ti ALLOY - GUM METAL DURING LOADING IN WIDE RANGE OF THE STRAIN RATES, ICPDF 2023, International Conference on Plasticity, Damage, and Fracture, 2023-01-03/01-09, Punta Cana (DM), pp.1-1, 2023
5.  Pieczyska E.A., Staszczak M., Maj M., Kuramoto S., GUM METAL SUBJECTED TO CYCLIC TENSION LOADING UP TO RUPTURE ANALYSED BY FAST AND SENSITIVE INFRARED CAMERA, ICDM4, The Fourth International Conference on Damage Mechanics, 2023-05-15/05-18, Baton Rouge, Louisiana (US), No.11, pp.1-1, 2023

Keywords:
Gum Metal, cyclic loading, infrared camera, thermomechanical coupling, rupture

Affiliations:
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Kuramoto S. - Ibaraki University Japan (JP)
6.  Pieczyska E., Golasiński K., Staszczak M., Janiszewski J., Sienkiewicz J., Takeda K., TI-BETA ALLOY - GUM METAL AND TINI SHAPE MEMORY ALLOY SUBJECTED TOCOMPRESSION LOADING IN WIDE RANGE OF THE STRAIN RATES, CMM-SolMech 2022, 24th International Conference on Computer Methods in Mechanics; 42nd Solid Mechanics Conference, 2022-09-05/09-08, Świnoujście (PL), No.279, pp.1-1, 2022
7.  Nabavian-Kalat M., Staszczak M., Ziai Y., Urbański L., Pieczyska E., Effect of Shape Recovery and Cyclic Loading on the Evolution of Micro-Cracks in Shape Memory Polymers, IUTAM Symposium, IUTAM Symposium on Enhancing Material Performance by Exploiting Instabilities and Damage Evolution, 2022-06-05/06-10, Warszawa (PL), DOI: 10.24423/iutam2022warsaw, No.P040, pp.54-54, 2022
8.  Staszczak M., Nabavian Kalat M., Urbański L., Cristea M., Pieczyska E.A., INFLUENCE OF STRAIN RATE AND COOLING RATE ON THE MECHANICAL BEHAVIOUR SHAPE MEMORY POLYURETHANE WITH Tg = 65 °C, ICEM, 19th International Conference on Experimental Mechanics, 2022-07-17/07-21, Kraków (PL), pp.280-281, 2022
9.  Pieczyska E.A., Golasiński K.M., Staszczak M., Janiszewski J., Sienkiewicz J., Kuramoto S., Takesue N., GUM METAL SUBJECTED TO COMPRESSION LOADING IN A WIDE SPECTRUM OF THE STRAIN RATES, ICEM, 19th International Conference on Experimental Mechanics, 2022-07-17/07-21, Kraków (PL), pp.270-271, 2022
10.  Nabavian Kalat M., Staszczak M., Ziai Y., Gradys A., Urbański L., Pieczyska E.A., THE EFFECT OF SHAPE MEMORY BEHAVIOR ON THE MICROSTRUCTURE OF THE PU-SMP (Tg = 45°C), ICEM, 19th International Conference on Experimental Mechanics, 2022-07-17/07-21, Kraków (PL), pp.278-279, 2022
11.  Nabavian K.M., Razzaghi-Kashani M., Pieczyska E., Staszczak M., The role of reduced graphene oxide as a secondary filler in reducing the energy dissipation of silica-filled styrene-butadiene rubber composites under dynamic deformation, TTP 2021, International Conference Thermography and Thermometry in Infrared, 2021-09-28/09-30, Kazimierz Dolny - on-line (PL), pp.1-2, 2021

Abstract:
Various quantities of reduced graphene-oxide (rGO) were added into silica-filled styrene-butadiene rubber (SBR) to make hybrid-filler composites. The non-linear viscoelastic behavior and corresponding energy dissipation of silica/rGO hybrid-filler and silica-filled composites were compared. Dynamic-mechanical analysis (DMA) of the hybrid-filler composites in strain-sweep showed that adding small quantity of rGO results in diminished silica network and reduced storage and loss modulus in silica-filled composites. Moreover, the synergy between silica and small quantities of rGO results in reduction of heat build-up (23%). The hybridization of silica/rGO was done without surface modification. This hybrid-filler system can be considered as an alternative to silane-modification of silica in industry.

Affiliations:
Nabavian K.M. - IPPT PAN
Razzaghi-Kashani M. - Tarbiat Modares University (IR)
Pieczyska E. - IPPT PAN
Staszczak M. - IPPT PAN
12.  Staszczak M., Pieczyska E., Nabavian K.M., Matsui R., Takeda K., Analiza energetyczna polimeru z pamięcią kształtu w procesie rozciągania, TTP 2021, International Conference Thermography and Thermometry in Infrared, 2021-09-28/09-30, Kazimierz Dolny - on-line (PL), pp.1-2, 2021

Abstract:
W ramach pracy przeprowadzono bilans energetyczny poliuretanu z pamięcią kształtu PU-SMP o temperaturze zeszklenia Tg = 25 °C w procesie rozciągania. Celem było oszacowanie ilości pracy mechanicznej niezbędnej do odkształcenia, ilości energii dyssypowanej oraz energii zmagazynowanej, tj. ukrytej w elementach zmienionej struktury tego polimeru. Dla wyższej prędkości odkształcania otrzymano wyższe wartości pracy zużytej na odkształcenie nieodwracalne oraz wyższe wartości ciepła dyssypowanego. Przeprowadzona analiza energetyczna procesu odkształcania wykazała, że praca zużyta na odkształcenie nieodwracalne nie magazynuje się w PU-SMP, tylko dysypuje. Może to mieć związek ze specyficzną budową polimeru z pamięcią kształtu, potwierdzoną przez badania strukturalne i odpowiadającą za jego właściwości.

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E. - IPPT PAN
Nabavian K.M. - IPPT PAN
Matsui R. - Aichi Institute of Technology (JP)
Takeda K. - Aichi Institute of Technology (JP)
13.  Pieczyska E.A., Golasiński K., Staszczak M., Janiszewski J., Sienkiewicz J., Ti alloy - Gum Metal subjected to compression in wide range of the strain rates, 64th Course: PROGRESS IN PHOTOACOUSTIC & PHOTOTHERMAL PHENOMENA, 2021-10-16/10-23, ERICE-SICILY (IT), No.C9, pp.52-52, 2021
14.  Staszczak M., Pieczyska E.A., Matsui R., Takeda K., Energy storage and dissipation in shape memory polyurethane, 64th Course: PROGRESS IN PHOTOACOUSTIC & PHOTOTHERMAL PHENOMENA, 2021-10-16/10-23, ERICE-SICILY (IT), No.C7, pp.50-50, 2021
15.  Golasiński K., Pieczyska E.A., Maj M., Staszczak M., Furuta T., Kuramoto S., Takesue N., Analysis of temperature changes of a Ti-based alloy gum metal under selected loadings in the context of its unconventional deformation mechanisms, 8th Wdzydzeanum Workshop on „FLUID – SOLID INTERACTION”, 2020-08-30/09-03, Wdzydze Kiszewskie (PL), pp.1-1, 2020
16.  Golasiński K.M., Pieczyska E.A., Maj M., Staszczak M., Takesue N., Thermomechanical behavior of gum metal under cyclic compression, PCM-CMM, 4th Polish Congress of Mechanics, 23rd International Conference on Computer Methods in Mechanics, 2019-09-08/09-12, Kraków (PL), pp.1, 2019

Keywords:
Gum Metal, Multifunctional Ti-based Alloy, Cyclic Compression, Infrared Thermography

Affiliations:
Golasiński K.M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Staszczak M. - IPPT PAN
Takesue N. - Fukuoka University (JP)
17.  Pieczyska E.A., Golasiński K.M., Maj M., Staszczak M., Furuta T., Kuramoto S., Gum metal subjected to tension at various strain rates - experimental results analysed by dic, PCM-CMM, 4th Polish Congress of Mechanics, 23rd International Conference on Computer Methods in Mechanics, 2019-09-08/09-12, Kraków (PL), pp.1, 2019

Keywords:
Gum metal, Titanium alloy, Tensile loading, Digital Image Correlation

Affiliations:
Pieczyska E.A. - IPPT PAN
Golasiński K.M. - IPPT PAN
Maj M. - IPPT PAN
Staszczak M. - IPPT PAN
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
18.  Pieczyska E.A., Golasiński K.M., Maj M., Staszczak M., Kuramoto S., Furuta T., Gum Metal mechanical properties investigated by infrared camera and digital image correlation, SMST, Shape Memory and Superelastic Technologies, 2019-05-13/05-17, Konstanz (DE), pp.1-2, 2019
19.  Staszczak M., Pieczyska E.A., Urbański L., Odriozola I., Martin R., Shape memory polymer subjected to thermomechanical loading - investigation of application parameter, ISMMS, 10th International Symposium on Mechanics of Materials and Structures, 2019-06-02/06-06, Augustów (PL), pp.105-106, 2019

Keywords:
shape memory polymer, shape fixity, shape recovery, thermomechanical loading program

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Urbański L. - IPPT PAN
Odriozola I. - IK4-CIDETEC (ES)
Martin R. - IK4-CIDETEC (ES)
20.  Pieczyska E.A., Golasiński K.M., Maj M., Staszczak M., Kuramoto S., Furuta T., Gum metal - a unique Ti alloy - investigated by digital image correlation and infrared thermography, ISMMS, 10th International Symposium on Mechanics of Materials and Structures, 2019-06-02/06-06, Augustów (PL), pp.86-87, 2019

Keywords:
Advanced material, Titanium alloy, Gum Metal, Superelasticity, High Strength, Tension, Infrared Camera, DIC

Affiliations:
Pieczyska E.A. - IPPT PAN
Golasiński K.M. - IPPT PAN
Maj M. - IPPT PAN
Staszczak M. - IPPT PAN
Kuramoto S. - Ibaraki University Japan (JP)
Furuta T. - Toyota Central Research & Development Laboratories (JP)
21.  Golasiński K.M., Pieczyska E.A., Maj M., Mackiewicz S., Staszczak M., Zubko M., Takesue N., Elastic and plastic anisotropy of gum metal investigated by ultrasound measurements and digital image correlation, ISMMS, 10th International Symposium on Mechanics of Materials and Structures, 2019-06-02/06-06, Augustów (PL), pp.43-44, 2019

Keywords:
Mechanical Anisotropy, Ti alloy, Gum Metal, Ultrasound Measurement, Digital Image Correlation

Affiliations:
Golasiński K.M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Mackiewicz S. - IPPT PAN
Staszczak M. - IPPT PAN
Zubko M. - other affiliation
Takesue N. - Fukuoka University (JP)
22.  Pieczyska E.A., Golasiński K.M., Maj M., Staszczak M., Kowalewski Z.L., Furuta T., Kuramoto S., Yielding and strain localization effects in gum metal - a unique ti alloy -investigated by digital image correlation and infrared thermography, 35 DANUBIA-ADRIA, 35th Danubia-Adria Symposium on Advances in Experimental Mechanics, 2018-09-25/09-28, Sinaia (RO), pp.57-58, 2018
23.  Golasiński K.M., Pieczyska E.A., Maj M., Staszczak M., Takesue N., Superelastic-like behavior of Gum Metal under compression inspected by infrared thermography, ESOMAT 2018, 11th European Symposium on Martensitic Transformations, 2018-08-27/08-31, Metz (FR), pp.84, 2018
24.  Golasiński K.M., Pieczyska E.A., Mackiewicz S., Staszczak M., Zubko M., Takesue N., Analysis Gum Metal crystallographic texture and misorientation in correlation to its mechanical behavior, CAC, XXIV CONFERENCE ON APPLIED CRYSTALLOGRAPHY, 2018-09-02/09-06, Arłamów (PL), No.OY1-5, pp.37-38, 2018

Keywords:
Gum Metal, EBSD, ultrasonic measurement

Affiliations:
Golasiński K.M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Mackiewicz S. - IPPT PAN
Staszczak M. - IPPT PAN
Zubko M. - other affiliation
Takesue N. - Fukuoka University (JP)
25.  Pieczyska E.A., Golasiński K.M., Maj M., Mackiewicz S., Staszczak M., Zubko M., Takesue N., Mechanical anisotropy of Gum Metal analyzed by ultrasonic measurements and digital image correlation, SolMech 2018, 41st SOLID MECHANICS CONFERENCE, 2018-08-27/08-31, Warszawa (PL), pp.352-353, 2018

Abstract:
Experimental investigation of mechanical anisotropy in a multifunctional beta titanium alloy Gum Metal under compression is reported. Non-destructive and destructive techniques were used to analyze unique mechanical behavior of the alloy. Structural characterization showed a strong <110> texture of Gum Metal, which is a result of cold-swaging applied during its fabrication [1]. Due to this kind of texture Gum Metal can be treated as transversally isotropic solid. Ultrasonic measurements determined elastic constants with high accuracy. A significant difference between Young's moduli of the alloy calculated for parallel and perpendicular directions to the alloy swaging direction was demonstrated. Compression of Gum Metal cube samples with two orientations was conducted on a testing machine. Two perpendicular walls of each sample were monitored by two visible range cameras during the deformation process for further 2-dimensional digital image correlation (DIC) analysis. Strong mechanical anisotropy of Gum Metal was confirmed by a detailed analysis of the stress vs. strain curves and strain distributions.

Affiliations:
Pieczyska E.A. - IPPT PAN
Golasiński K.M. - IPPT PAN
Maj M. - IPPT PAN
Mackiewicz S. - IPPT PAN
Staszczak M. - IPPT PAN
Zubko M. - other affiliation
Takesue N. - Fukuoka University (JP)
26.  Staszczak M., Pieczyska E.A., Matsui R., Takeda K., Estimation of energy storage and dissipation in Shape Memory Polymer during its deformation, SolMech 2018, 41st SOLID MECHANICS CONFERENCE, 2018-08-27/08-31, Warszawa (PL), pp.338-339, 2018
27.  Staszczak M., Pieczyska E.A., Odriozola I., Martin R., Investigation of functional properties of new shape memory polymer, ICEM 2018, 18TH INTERNATIONAL CONFERENCE ON EXPERIMENTAL MECHANICS, 2018-07-01/07-05, BRUKSELA (BE), No.199, pp.1-2, 2018
28.  Pieczyska E.A., Golasiński K.M., Maj M., Staszczak M., Mackiewicz S., Zubko M., Takesue N., Gum metal in compression – investigation of mechanical anisotropy caused by texture, ICEM 2018, 18TH INTERNATIONAL CONFERENCE ON EXPERIMENTAL MECHANICS, 2018-07-01/07-05, BRUKSELA (BE), No.454, pp.1-2, 2018
29.  Pieczyska E.A., Staszczak M., Golasiński K.M., Maj M., Tobushi H., Kuramoto S., Furuta T., Investigation of Shape Memory Alloys, Polymers and Gum Metals for Biomedical Applications, Materials Science and Nanoscience 2-d Global Congress and Expo, 2017-09-25/09-27, Valencia (ES), pp.1, 2017
30.  Golasiński K.M., Pieczyska E.A., Maj M., Staszczak M., Takesue N., Unique mechanical performance of an innovative Ti-based superalloy Gum Metal under compression, International Scientific Conference Humboldt-Kolleg Limits of Knowledge, 2017-06-22/06-25, Cracow (PL), pp.P35-NS-218-219, 2017
31.  Golasiński K.M., Pieczyska E.A., Staszczak M., Cristea M., Experimental investigation of thermomechanical properties of multifunctional materials at IPPT PAN, MACRO Iasi, The XXVI-th Symposium PROGRESS IN ORGANIC AND POLYMER CHEMISTRY, 2017-10-05/10-06, Jassy (RO), pp.1-1, 2017
32.  Pieczyska E.A., Golasiński K.M., Staszczak M., Maj M., Furuta T., Kuramoto S., A thermomechanical analysis of high elasto-plastic properties of gum metal at various strain rates, M2D, 7th International Conference on Mechanics and Materials in Design, 2017-06-11/06-15, Albufeira (PT), pp.393-394, 2017

Abstract:
Mechanical characteristics obtained by MTS testing machine and digital image correlation (DIC) algorithm as well as the related temperature changes in a new B-Ti alloy - Gum Metal, subjected to tension in a wide spectrum of the strain rates, are presented The fast and sensitive infrared camera ThermaCam Phoenix allowed estimating temperature changes accompanying the specimen deformation process in contactless manner. The obtained mechanical curves confirm an ultra-low elastic modulus and high strength of Gum Metal. Furthermore, it was presented how the stress-strain characteristics change from hardening to softening depending on the strain rate. The thermoelastic effect, estimated by the IR technique was discussed according to the Gum Metal yield point.

Keywords:
gum metal, titanium alloy, tension test, strain rate, thermomechanical coupling

Affiliations:
Pieczyska E.A. - IPPT PAN
Golasiński K.M. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
33.  Golasiński K.M., Pieczyska E.A., Maj M., Staszczak M., Takesue N., Investigation of Gum Metal under compressive cyclic loading, Plastmet 2016, Jubileuszowe X Seminarium Naukowe ZINTEGROWANE STUDIA PODSTAW DEFORMACJI PLASTYCZNEJ METALI, 2016-11-22/11-25, Łańcut (PL), pp.41-42, 2016

Abstract:
Preliminary results of mechanical behavior of Gum Metal compressed along the swaging direction during cyclic loading were presented. The unique mechanical performance of Gum Metal - low Young’s Modulus and high strength were confirmed. During the cyclic loading the curves profiles change significantly with each cycle and reveal a clearly pronounced yield points for the 4th and further cycles. Compression tests along perpendicular direction to the swaging one will be considered for our future research.

Keywords:
Gum Metal, polycrystal, compression loading, cyclic loading, digital image correlation

Affiliations:
Golasiński K.M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Staszczak M. - IPPT PAN
Takesue N. - Fukuoka University (JP)
34.  Pieczyska E.A., Staszczak M., Tobushi H., Takeda K., Matsui R., Hayashi S., Shape memory polymer - influence of temperature, strain rate and the loading history on the stress-strain curves, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P194, pp.1-2, 2016

Abstract:
The mechanism of exhibiting shape memory property in polymer is different from that observed in shape memory alloy, since the crystallographic phase transformation does not occur in polymers. The functional characteristics of shape memory polymer (SMP), e.g. rigidity, elastic modulus and coefficient of thermal expansion, change significantly above and below its glass transition temperature (Tg) due to molecular motion of the polymer chains which differs drastically below and above Tg. These properties allow to apply SMP in biomedical, textile, housing, transportation, aviation industries. A goal of this paper is to discuss selected results of the SMP investigation and demonstrate how significantly its mechanical properties change in various conditions; influence of temperature, strain rate and loading history were taken into consideration.

Keywords:
Shape memory polymer, tensile test, strain rate, temperature change

Affiliations:
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Takeda K. - Aichi Institute of Technology (JP)
Matsui R. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
35.  Staszczak M., Pieczyska E.A., Tobushi H., Thermomechanical analysis of polyurethane shape memory polymer in cyclic loading – shape recovery and shape fixity, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P189, pp.1-2, 2016

Abstract:
Recently shape memory polymers (SMP) have been attracting broad interest because they can change their shape in a predefined way when exposed to an appropriate stimulus. Among the shape memory polymers the largest group represent those, whose shape memory properties are triggered by temperature. The temperature at which the polymer returns to the original shape is usually its glass transition temperature (Tg). If the polymer is heated to the temperature above Tg, it can be deform easily. After cooling down below its Tg, followed by unloading to remove the stress, the modified shape is largely maintained (shape fixity). Heating again to temperature above the Tg enables the polymer to return to the original shape (shape recovery). Thermally responsive polymers found applications in various fields, e.g. in smart textiles, in medical devices, in actuators and sensors, heat-shrinkable tubes for electronics, etc. In order to guarantee sufficient reliability and predict the shape memory behavior of these materials it is important to obtain knowledge about the shape fixity and shape recovery properties.

Keywords:
Shape memory polymer, cyclic loading, shape fixity, shape recovery, thermomechanical analysis

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
36.  Pieczyska E.A., Golasiński K.M., Staszczak M., Maj M., Furuta T., Kuramoto S., Gum metal subjected to cyclic tension loading analysed by fast and sensitive infrared camera, ICMFM18, XVIII International Colloquium MECHANICAL FATIGUE OF METALS, 2016-09-05/09-07, Gijón (ES), pp.1, 2016

Abstract:
Gum Metal, a new multifunctional titanium alloy combining high elasticity of rubber and strength of metal, has been mechanically and thermomechanically tested. The subsequent tension deformation cycles have been conducted. At the strain rate of 10-2s-1 and step of 0.005 - 37 loading-unloading cycles until rupture were performed. Comparison of stress and temperature changes vs. strain for 2nd, 20th and 36th loading-unloading cycles is discussed.

Keywords:
Gum Metal, cyclic loading, infrared camera, thermomechanical coupling

Affiliations:
Pieczyska E.A. - IPPT PAN
Golasiński K.M. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
37.  Golasiński K.M., Pieczyska E.A., Staszczak M., Furuta T., Kuramoto S., Thermomechanical Investigation of Gum Metal – a New Innovative Titanium Alloy for Biomedical Applications, The 10th International Congress of Societas Humboldtiana Polonorum “Longevity - a blessing or a curse”, 2016-06-30/07-02, Łódź (PL), pp.43, 2016

Keywords:
Gum metal, biomedical application, superelastic properties

Affiliations:
Golasiński K.M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
38.  Pieczyska E.A., Golasiński K.M., Staszczak M., Maj M., Furuta T., Kuramoto S., High elasto-plastic properties of new titanium alloy gum metal in wide spectra of the strain rates, 17th International Conference on Experimental Mechanics, 2016-07-03/07-07, Rhodes (GR), No.388, pp.1-2, 2016

Abstract:
Results of investigation of mechanical properties and the related temperature changes in a β-Ti alloy, Gum Metal, subjected to tension in a wide spectrum of the strain rates are presented. The stress-strain curves have been obtained by MTS testing machine while fast and sensitive infrared camera Phoenix Flir Co. allowed estimating temperature changes accompanying the specimen deformation process. The obtained mechanical curves confirm an ultra- low elastic modulus and high strength of Gum Metal. The yield point was estimated with high accuracy basing on the thermoelastic effect measured by the advanced infrared technique. Furthermore, it was observed that the stress-strain characteristics change from hardening to softening beyond the Yield point depending on the strain rate applied.

Keywords:
Gum metal, Titanium alloy, Superelastic nonlinear properties, strain rate

Affiliations:
Pieczyska E.A. - IPPT PAN
Golasiński K.M. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
39.  Golasiński K.M., Pieczyska E.A., Staszczak M., Maj M., Furuta T., Kuramoto S., Thermomechanical behavior of gum metal under cyclic loading, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P208, pp.1-2, 2016

Abstract:
This work presents thermomechanical characterization of a new multifunctional class of β-Ti alloy called Gum Metal subjected to cyclic tensile loading. Being developed in the Toyota Central R&D Laboratory (CRDL), Gum Metal has attracted remarkable attention due to its exceptional properties, i.e. low elastic modulus, high strength, nonlinear elastic deformation, excellent cold workability as well as Invar- and Elinvar-like behavior. Typical composition of Gum Metal is Ti-Nb-Ta-Zr-O, where oxygen content plays a key role. Its fabrication route consists of powder metallurgy forging method with subsequent cold working usually up to 90% in area reduction. The latter is critical for the unique mechanical performance but deformation mechanisms occurring in Gum Metal are unconventional and still unclear.

Keywords:
Gum metal, cyclic loading, titanium alloy, thermomechanical behavior

Affiliations:
Golasiński K.M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Furuta T. - Toyota Central Research & Development Laboratories (JP)
Kuramoto S. - Ibaraki University Japan (JP)
40.  Staszczak M., Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Cristea M., Tobushi H., Hayashi S., Shape memory polymer – shape fixity and recovery in cyclic loading, PCM-CMM 2015, 3rd Polish Congress of Mechanics and 21st Computer Methods in Mechanics, 2015-09-08/09-11, Gdańsk (PL), pp.147-148, 2015

Abstract:
The paper concerns investigation of polyurethane shape memory polymer (SMP) properties. Shape fixity and shape recovery, important parameters for the SMP applications, were quantitatively estimated in thermomechanical cyclic loading; three subsequent thermomechanical loading cycles were performed. It was observed that the shape fixity is proper and does not depend on the cycle number. The obtained mean values of shape fixity parameters are 97-98 %. Although the shape recovery is poor (=83 %) in the first cycle of the thermomechanical loading, it is excellent in the subsequent cycles (=99-100 %). The evaluated parameters confirm good shape memory properties of the SMP.

Keywords:
Shape memory polyurethane, shape fixity, shape recovery, thermomechanical loading, cyclic loading

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
41.  Kukla D., Staszczak M., Pieczyska E.A., Heljak M., Szlązak K., Święszkowski W., Cristea M., Tobushi H., Hayashi S., Evaluation of the properties of polymeric foams with shape memory under load, PCM-CMM 2015, 3rd Polish Congress of Mechanics and 21st Computer Methods in Mechanics, 2015-09-08/09-11, Gdańsk (PL), pp.143-144, 2015

Abstract:
The paper presents the results of experimental investigation on polymer foam with shape memory properties. The research is focused on characterization of the microstructure of the foam and understanding the mechanisms of deformation under static and dynamic loading. Up till now, selected experimental techniques have been applied. Dynamic Mechanical Analysis (DMA) allows determining the extent of the value of the glass transition temperature under different load conditions, which also reveals the transformation temperature range for the SMP foam. Scanning electron microscopy (SEM) shows the foam microstructure in various scales, while X-ray tomography gave 3D microstructure results presenting in addition mechanism of the cells deformation and changes in their geometry under 30 % and 50% strain. BOSE system enables obtaining the results on dynamic loading.

Keywords:
Shape memory polymer foam, Dynamic mechanical analysis, Glass transition temperature, X-ray tomography

Affiliations:
Kukla D. - IPPT PAN
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Heljak M. - Warsaw University of Technology (PL)
Szlązak K. - other affiliation
Święszkowski W. - other affiliation
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
42.  Pieczyska E.A., Staszczak M., Maj M., Kowalczyk-Gajewska K., Tobushi H., Właściwości termomechaniczne i zastosowania polimerów z pamięcią kształtu, XI Konferencja Nowe Kierunki Rozwoju Mechaniki, 2015-03-18/03-20, Sarbinowo (PL), pp.75-76, 2015

Abstract:
Polimery z pamięcią kształtu, podobnie jak niektóre stopy metali, wykazują efekt pamięci kształtu. Wykorzystuje się w nich różnicę właściwości termomechanicznych poniżej i powyżej temperatury zeszklenia Tg, w której polimer radykalnie zmienia swe własności, m.in. wartość modułu sprężystości. Materiały te posiadają możliwość szybkiej zmiany właściwości fizycznych w zależności od temperatury. Stają się miękkie po podgrzaniu powyżej Tg i pozwalają się łatwo formować, a podczas schłodzenia poniżej tej temperatury odzyskują poprzednią sztywność. Nadal pamiętają swój oryginalny kształt i wracają do niego podczas ponownego podgrzania powyżej Tg. Umożliwia to ich różnorodne praktyczne zastosowania, m.in. w przemyśle medycznym i farmaceutycznym, tekstylnym, spożywczym, lotniczym i kosmicznym.

Keywords:
Polimery z pamięcią kształtu, temperatura zeszklenia, wartość modułu sprężystości, kamera termowizyjna

Affiliations:
Pieczyska E.A. - IPPT PAN
Staszczak M. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
43.  Staszczak M., Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Cristea M., Tobushi H., Hayashi S., Estimation of shape fixity and shape recovery – crucial parameters for shape memory polymer applications, SolMech 2014, 39th Solid Mechanics Conference, 2014-09-01/09-05, Zakopane (PL), pp.267-268, 2014

Abstract:
Shape memory polymers (SMP) are new unique and attractive materials which demonstrate shape memory properties. It means that the materials, as a result of an external stimulus such as temperature, can recover their original (permanent) shape from deformed (temporary) shape. The mechanical characteristics of SMP, e.g. the elastic modulus and the yield stress, change significantly below and above their glass transition temperature Tg. It can be explained by differences of molecular motion of the polymer chains below and above Tg [1, 2]. Two phenomena due to this can be observed in the SMP. The first one is a shape fixity which means that it is possible to fix a temporary shape by cooling the deformed SMP below Tg. The second phenomenon, called a shape recovery, denotes the property that the original shape, changed due to deformation, is recovered during subsequent heating above the SMP Tg temperature. Preliminary estimation of these two parameters, crucial to assess SMP potential applications, is the subject of this paper [1].

Keywords:
Shape memory polymers, elastic modulus, yield stress, glass transition temperature, shape fixity, shape recovery

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
44.  Kowalczyk-Gajewska K., Pieczyska E.A., Maj M., Staszczak M., Majewski M., Cristea M., Tobushi H., Two-phase model of shape memory polymers at finite strains: formulation and experimental verification, SolMech 2014, 39th Solid Mechanics Conference, 2014-09-01/09-05, Zakopane (PL), pp.259-260, 2014

Abstract:
A constitutive model of SMP, formulated at large strain format, is developed. SMP is described as a two-phase material composed of a soft rubbery phase and a hard glassy phase. The volume fraction of each phase is postulated as a logistic function of temperature. Identification of model parameters has been performed using the experimental tensile loading-unloading tests with different strain rates conducted at thermal chamber at different temperatures.

Keywords:
shape-memory polymers, two-phase model, large strain framework

Affiliations:
Kowalczyk-Gajewska K. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Staszczak M. - IPPT PAN
Majewski M. - IPPT PAN
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H. - Aichi Institute of Technology (JP)
45.  Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Staszczak M., Tobushi H., Hayashi S., Cristea M., Thermomechanical analysis of shape memory polymer under cyclic loading and relaxation conditions, ICEM-16, 16th International Conference on Experimental Mechanics, 2014-07-07/07-11, Cambridge (GB), pp.1-2, 2014

Abstract:
Experimental evaluation and modeling of a new polyurethane shape memory polymer (SMP) subjected to cyclic tension and stress-relaxation tests are presented. The influence of effects of thermomechanical couplings on the SMP thermomechanical behaviour for various strain rates was studied, basing on the sample temperature changes measured by a fast and sensitive infrared camera. The constitutive model valid in finite strain regime was developed following [5]. In the proposed approach SMP is described as a two-phase material composed of hyperelastic rubbery phase and elastic-viscoplastic glassy phase while the volume content of phases is specified by the current temperature.

Keywords:
Experimental evaluation, constitutive modeling, polyurethane shape memory polymer, cyclic tension, stress-relaxation tests, effects of thermomechanical couplings, thermomechanical behaviour, various strain rates, temperature changes, sensitive infrared camera, hyperelastic rubbery phase, elastic-viscoplastic glassy phase

Affiliations:
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Staszczak M. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
46.  Pieczyska E.A., Tobushi H., Hayashi S., Maj M., Staszczak M., Shape memory alloys and polymers studied in tension by advanced infrared technique, DAS 30, 30th Danubia-Adria-Symposium on Advances in Experimental Mechanics, 2013-09-25/09-28, Primosten (HR), Vol.1, pp.24-25, 2013

Abstract:
In order to contribute to solving the problems of recourses, energy and environment of the earth, the development of multifunctional smart materials is required. In the intelligent materials, investigation of shape memory alloy (SMA) and shape memory polymer (SMP) has attracted high attention due to their functional properties and high potential in practical applications. In SMA, the shape memory property appears based on the martensitic transformation (MT) in which the crystal structure varies depending on the variation in stress or temperature. In SMP, the elastic modulus and the yield stress are high at temperatures below the glass transition temperature Tg and low at temperatures above Tg. The shape memory property appears based on the glass transition in which the characteristics of molecular motion vary depending on the variation in temperature. Among the shape memory polymers, the polyurethane has been most often practically used.
In this paper, investigation of stress-induced martensitic transformation in TiNi SMA and thermomechanical behavior of SMP (Tg = 19 C) in tension at room temperature (22 C) are presented.

Keywords:
shape memory alloy, shape memory polymer, thermomechanical couplings, tensile test, strain localisation

Affiliations:
Pieczyska E.A. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
Maj M. - IPPT PAN
Staszczak M. - IPPT PAN
47.  Staszczak M., Pieczyska E.A., Maj M., Urbański L., Tobushi H., Hayashi S., Właściwości mechaniczne oraz zmiany temperatury polimeru z pamięcią kształtu w procesie rozciągania, TTP2013, X Konferencja TERMOGRAFIA I TERMOMETRIA W PODCZERWIENI, 2013-09-24/09-26, Lwów (UA), Vol.1, pp.91-92, 2013

Abstract:
W pracy przedstawiono wyniki badań efektów sprzężeń termomechanicznych poliuretanu z pamięcią kształtu podczas rozciągania z różnymi prędkościami. Zależności zmiany temperatury próbek od czasu wyznaczano za pomocą kamery termograficznej. Zaobserwowano dużą wrażliwość charakterystyk mechanicznych i zmian temperatury poliuretanu na prędkość deformacji. Wykorzystując efekt piezokaloryczny wyznaczano granice plastyczności dla różnych prędkości odkształcenia. Pokazano, że metoda bazująca na minimum temperatury próbki jest przydatna do wyznaczania granicy plastyczności materiałów polimerowych wykazujących nieliniową sprężystość.

Keywords:
poliuretan z pamięcią kształtu, efekty sprzężeń termomechanicznych, kamera termograficzna, efekt piezokaloryczny, granica plastyczności

Affiliations:
Staszczak M. - IPPT PAN
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Urbański L. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
48.  Pieczyska E.A., Tobushi H., Hayashi S., Maj M., Kowalczyk-Gajewska K., Staszczak M., Cristea M., Thermomechanical Analysis of Shape Memory Polyurethane, 4th Integrity, Reliability and Failure of Mechanical Systems, 2013-06-23/06-27, Funchal (PT), pp.1-2, 2013

Abstract:
This paper presents experimental evaluation of a new polyurethane shape memory polymer (PU-SMP) produced by SMP Technologies Inc. It discusses mechanical characteristics and temperature changes of the SMP specimens subjected to tension test performed at room temperature with various strain rates. Basing on the mechanical data and the relevant temperature changes, we have studied the thermomechanical properties of the PU-SMP and influence of the strain rate on the strain localization behavior. Finally, we have identified the material parameters for the one-dimensional rheological model of the SMP.

Keywords:
shape memory polyurethane, tension test, dynamic mechanical analysis, infrared camera, temperature change, thermomechanical properties, rheological model

Affiliations:
Pieczyska E.A. - IPPT PAN
Tobushi H. - Aichi Institute of Technology (JP)
Hayashi S. - SMP Technologies Inc. (JP)
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Staszczak M. - IPPT PAN
Cristea M. - Petru Poni Institute of Macromolecular Chemistry (RO)
49.  Pieczyska E.A., Maj M., Kowalczyk-Gajewska K., Staszczak M., Mechanical and Infrared Thermography Analysis of Shape Memory Polyurethane, International Conference on Shape Memory and Superelastic Technologies, 2013-05-20/05-24, Praga (CZ), pp.282-283, 2013

Abstract:
Initial experimental evaluation of a new polyurethane shape memory polyner (PU-SMP) subjected to uniaxial tension carrięd out at different stlain rates is presented. The stress and strain data were recorded and temperature changes from the SMP specimen surface was deternrined using fast and sensitive infrared camera. Basing on themechanical characteristics and their relevant temperature changes, the SMP thernromechanical properties have been stLrdied. lnfluence of the strain rate on the SMP temperature, its structure and behaviour are discussed. Identification of the PU-SMP parameters for onc-dimensional rheological model proposed by Tobushi et. ttl. will be performed.

Keywords:
Shape memory polymers, elastic modulus, yield stress, glass transition temperature

Affiliations:
Pieczyska E.A. - IPPT PAN
Maj M. - IPPT PAN
Kowalczyk-Gajewska K. - IPPT PAN
Staszczak M. - IPPT PAN

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