Crystal plasticity extend FEM implementation of thermal-tensile aluminum alloy

Yang Liu,Ping Hu,Yiguo Zhu,Liang Ying,K Saanouni

doi:10.1051/matecconf/20168002015

Yang Liu, Ping Hu + Show 3 more

Open Access

https://doi.org/10.1051/matecconf/20168002015

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Abstract

Multi-level approach has been used to simulate the thermal deformation of aluminium alloy at different temperature and strain rate. The crystal plasticity model is extended in the finite element method and the thermal behaviour is integrated in the constitutive equations. Moreover, the damage evolution is also reflected in the simulation using continuum damage mechanics model. Thus, the void evolution and thermal effect could both be shown in the simulation. A new shear strain rate model is constructed with the thermal activated mechanism to describe the rate dependent behaviours during tensile test. The thermal parameters are determined in a fitting test of representative volume element to compare with the experimental data. The results prove that the mechanical tensile behaviour of 5052 aluminium alloy could be well described at different temperatures. The damage evolution process is expressed by the stress concentration and strain concentration in the finite element simulation, which are also confirmed by the experiments.

Highlights

Aluminium alloy has become one of most popular metal in the vehicle industry
The crystal plasticity model is coupled with thermal effect and damage evolution, which is inserted in the subroutine Use-defined Material Mechanical Behaviour (UMAT) of commercial software ABAQUS
The damage evolution process is simulated in the ABAQUS, and the subroutine UMAT is implemented

Summary

Introduction

Aluminium alloy has become one of most popular metal in the vehicle industry. The steel is replacing by the aluminium alloy for reducing the weight and protecting the environment. In addition to the deformation, the crystallographic anisotropy leads to the different kinds of orientation dependent behaviours, such as strain hardening and void evolution In this sense, to better understand the relationship between material property and microstructure of aluminium alloy, various multi-level polycrystalline schemes are built and developed to describe this orientation property such as Taylor and Saches models. As for thermal effects, a visco-plastic self-consistent (VPSC) model is generally used to homogenize the polycrystal and calculate the mechanical behaviour as a function of strain rate and temperature [6] This advanced mean-field scheme is able to simulate the temperature field coupled with mechanical field, but still lack of capturing codeformation within grains.

Framework of Crystal Plasticity Extended Finite Element Method

Figures and tables

Thermal tensile simulation

Conclusion and discussion