| 1. |
Długosz A.♦, Pokorska I., Jaskulski R., Glinicki M.A., Evolutionary identification method for determining thermophysical parameters of hardening concrete,
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1007/s43452-020-00154-7, Vol.21, pp.35-1-14, 2021 Abstract:
The kinetics of heat transfer in hardening concrete is a key issue in engineering practice for erecting massive concrete structures. Prediction of the temperature fields in early age concrete should allow for proper control of the construction process to minimize temperature gradients and the peak temperatures, which is of particular importance for concrete durability. The paper presents a method of identification of the thermophysical parameters of early age concrete such as the thermal conductivity, the specific heat, and the heat generated by cement hydration in time. Proper numerical models of transient heat conduction problems were formulated by means of finite-element method, including two types of heat losses. The developed experimental–numerical approach included the transient temperature measurements in an isolated tube device and an in-house implementation of an evolutionary algorithm to solve the parameter identification task. Parametric Bezier curves were proposed to model heat source function, which allowed for identifying such function as a smooth curve utilizing a small number of parameters. Numerical identification tasks were solved for experimental data acquired on hardening concrete mixes differing in the type of cement and type of mineral aggregate, demonstrating the effectiveness of the proposed method (the mean-squared error less than 1 °C). The proposed approach allows for the identification of thermophysical parameters of early age concrete even for mixtures containing non-standard components while omitting drawbacks typical for classical optimization methods. Keywords:
early age concrete, evolutionary algorithm, inverse solution, heat transfer problem, mass concrete, thermal properties Affiliations:
| Długosz A. | - | Silesian University of Technology (PL) | | Pokorska I. | - | IPPT PAN | | Jaskulski R. | - | IPPT PAN | | Glinicki M.A. | - | IPPT PAN |
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| 2. |
Długosz A.♦, Pokorska I.♦, Glinicki M.A., Jaskulski R.♦, Identification of thermal properties of hardening concrete by means of evolutionary algorithms,
COMPUTER ASSISTED METHODS IN ENGINEERING AND SCIENCE, ISSN: 2299-3649, Vol.24, pp.101-111, 2017Abstract:
In this paper, the evolutionary computation procedures for identifying thermophysical properties in hardening massive concrete structures are presented. The heat of cement hydration, thermal conductivity and specific heat are determined for the purpose of modeling temperature evolution in massive concrete elements. Knowledge about temperature fields is very important due to their link with undesirable thermal stresses that can cause a weakening of structures because of thermal cracking. The proposed method is based on point temperature measurements in a cylindrical mould and the numerical solution of the inverse heat transfer problem by means of the finite element method and evolutionary computation Keywords:
thermal properties of concrete, inverse heat transfer problem, early age concrete, evolutionary algorithm, FEM Affiliations:
| Długosz A. | - | Silesian University of Technology (PL) | | Pokorska I. | - | other affiliation | | Glinicki M.A. | - | IPPT PAN | | Jaskulski R. | - | other affiliation |
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| 3. |
Długosz A.♦, Burczyński T.♦, Multiobjective shape optimization of selected coupled problems by means of evolutionary algorithms,
BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.2478/v10175-012-0028-3, Vol.60, No.2, pp.215-222, 2012Abstract:
In present paper an improved multi-objective evolutionary algorithm is used for Pareto optimization of selected coupled problems. Coupling of mechanical, electrical and thermal fields is considered. Boundary-value problems of the thermo-elasticity, piezoelectricity and electro-thermo-elasticity are solved by means of finite element method (FEM). Ansys Multiphysics and MSC.Mentat/Marc software are used to solve considered coupled problems. Suitable interfaces between optimization tool and the FEM software are created. Different types of functionals are formulated on the basis of results obtained from the coupled field analysis. Functionals depending on the area or volume of the structure are also proposed. Parametric curves NURBS are used to model some optimized structures. Numerical examples for exemplary three-objective optimization are presented in the paper. Keywords:
multiobjective optimization, evolutionary algorithms, multiphysics, coupled field problems, finite element method Affiliations:
| Długosz A. | - | Silesian University of Technology (PL) | | Burczyński T. | - | other affiliation |
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| 4. |
Białecki R.A.♦, Burczyński T.♦, Długosz A.♦, Kuś W.♦, Ostrowski Z.♦, Evolutionary shape optimization of thermoelastic bodies exchanging heat by convection and radiation,
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING, ISSN: 0045-7825, DOI: 10.1016/j.cma.2004.07.004, Vol.194, No.17, pp.1839-1859, 2005Abstract:
Shape optimization of heat conducting, elastic bodies subjected to thermal and standard loads is considered. Interaction of stress and temperature fields is modelled using the formulation of steady state thermoelasticity. The presence of heat radiation with mutual irradiation of the boundaries and the presence of shadow zones is taken into account. Evolutionary algorithm is used to evaluate the optimal shape. The boundary element method is applied to discretize the thermoelasticity, conduction and radiation problems. Keywords:
Evolutionary algorithm, Shape optimization, Thermoelasticity, Radiation, Stress, BEM, Parallel computing Affiliations:
| Białecki R.A. | - | Silesian University of Technology (PL) | | Burczyński T. | - | other affiliation | | Długosz A. | - | Silesian University of Technology (PL) | | Kuś W. | - | Silesian University of Technology (PL) | | Ostrowski Z. | - | other affiliation |
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