engleski

Low cycle fatigue and elasto-plastic material behaviour simulation

Modelling of material behaviour has significant influence on design and optimization of mechanical structures and consequently calculation of their lifetime. There are numerous material models in use today. They vary in their complexity and offer knowledge of various material behaviour characteristics. Material model presented in this paper describes elasto-plastic behaviour of the material. It takes into account damage occurrence and accumulation in the material and its relation to isotropic and kinematic hardening. The material constitutive model is highly non-linear and therefore its parameter identification requires complex numerical procedure, such as genetic algorithm. Because of its complexity, the unique genetic operators’ routines in genetic algorithm calculation procedure are developed to make possible fast and reliable convergence to the results. These routines, chosen to build an optimal genetic algorithm procedure, are proposed in this paper. Genetic algorithm proved to be a good method for material parameters identification. The procedure is validated by comparing simulated material response in different loading conditions with a real one. The experiments for this comparison are performed on testing specimens made out of steel 42CrMo4, loaded to make possible low cycle fatigue and elasto-plastic material behaviour analysis.

fatigue; material model; genetic algorithm; simulation

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