engleski

Automation of LCF Material Model Parameters’ Identification

Modelling of material behaviour has significant influence on design and optimization of mechanical structures and consequently calculation of their lifetime. When using complex constitutive material models, like one that describes elasto–plastic behaviour of the cyclically loaded material and takes into account damage occurrence and accumulation, the process of parameter identification from experimental data is very complex and time-consuming. The material model considered in this paper is based on continuum mechanics theory and theory of damage mechanics. The damage occurrence and accumulation within the material are described by means of models of Bauschinger effect, kinematic and isotropic hardening (or softening) according to Chaboche material model and mean stress relaxation according to Ohno-Wang material model. Since the material model is highly non-linear, it’s parameter identification requires complex numerical procedures, optimaly chosen algorithms and numerical operators, followed by software solution development. The developed automated system for parameter identification is validated by comparing the calculated with experimental response of the material. It’s usage makes modelling material behaviour for numerous materials accurate, fast and user friendly. Additional advantage of the current system is that it can be further developed to be used for different constitutive material models.

Fatigue; Constitutive behaviour; Elastic-plastic material; Finite element; Numerical algorithm

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