Partner: Halina Egner

Cracow University of Technology (PL)

Supervision of doctoral theses
1.2019-04-17Ryś Maciej  
(Politechnika Krakowska)
Modelling of damage evolution in multiphase engineering materials 

Recent publications
1.Ryś M., Egner H., Energy equivalence based constitutive model of austenitic stainless steel at cryogenic temperatures, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, ISSN: 0020-7683, DOI: 10.1016/j.ijsolstr.2018.12.028, Vol.164, pp.52-65, 2019
Abstract:

In the present work the constitutive model of 316L and 304 stainless steel subjected to mechanical loading at cryogenic temperatures is derived. Three main coupled dissipative phenomena taking place in the material: plastic flow, plastic strain-induced transformation from the primary phase (γ) to the secondary phase (α′), and evolution of micro-damage are considered using a thermodynamically consistent framework. The approach based on total energy equivalence, originally developed for damaged materials, is here extended to modelling not only damage but also phase transformation, in a consistent manner. The proposed model is implemented numerically and validated by means of parametric studies, and by comparison with the experimental results. Very good qualitative and quantitative results are obtained.

Keywords:

constitutive modelling, plasticity, damage, phase transformation, cryogenic temperatures

Affiliations:
Ryś M.-IPPT PAN
Egner H.-Cracow University of Technology (PL)
2.Egner H., Ryś M., Total energy equivalence in constitutive modeling of multidissipative materials, INTERNATIONAL JOURNAL OF DAMAGE MECHANICS, ISSN: 1056-7895, DOI: 10.1177/1056789516679496, Vol.26, No.3, pp.417-446, 2017
Abstract:

In the present work, the total energy equivalence hypothesis was applied in constitutive modeling of engineering materials. The approach originally developed for damaged materials, was extended to modeling not only damage but also other dissipative phenomena, like phase transformation, in a consistent manner. The proposed model was examined by means of parametric studies to show its ability to reflect different experimentally observed features of real materials.

Keywords:

Constitutive modeling, dissipative material, plasticity, damage, phase transformation

Affiliations:
Egner H.-Cracow University of Technology (PL)
Ryś M.-IPPT PAN
3.Egner H., Skoczeń B., Ryś M., Constitutive and numerical modeling of coupled dissipative phenomena in 316L stainless steel at cryogenic temperatures, International Journal of Plasticity, ISSN: 0749-6419, DOI: 10.1016/j.ijplas.2014.08.005, Vol.64, pp.113-133, 2015
Abstract:

A macroscopic material model for simulation of coupled dissipative phenomena taking place in FCC metals and alloys at low temperatures is developed. Three phenomena: plastic flow, plastic strain induced transformation from the parent phase ( to the secondary phase ( and evolution of micro-damage are studied using a thermodynamically consistent framework. The experimental results indicate a correlation between decreasing damage rate and increasing martensite content. For the micro-damage evolution in the parent austenitic phase a generalization of the classical isotropic ductile damage concept to anisotropic model has been adopted. The kinetics of damage evolution is based on the accumulated plastic strain as a driving force of ductile damage. On the other hand, the deterioration of the brittle secondary phase is described by the damage evolution equation expressed in the form of tensorial function, where the damage tensor depends directly on the stresses applied. This formulation accounts both for the isotropic damage, and for the oriented damage due to different effects of the stress tensor. Total amount of damage in the representative volume element is obtained via the linear rule of mixture. The results obtained in the course of numerical simulations fit well the experimental data

Keywords:

B. Constitutive behavior, A. Microcracking, A. Phase transformation, Cryogenic temperature

Affiliations:
Egner H.-Cracow University of Technology (PL)
Skoczeń B.-Cracow University of Technology (PL)
Ryś M.-other affiliation