Micro-mechanical numerical analysis on ductile damage in multiaxially loaded anisotropic metals

The paper deals with numerical analysis of the effect of stress state and loading direction with respect to the rolling direction on damage and fracture behavior of anisotropic metals. The continuum damage model has been enhanced to take into account the influence of production-induced anisotropies and loading direction on damage criteria and on evolution equations of damage strains. Constitutive parameters are determined using experimental results taken from tests with uni- and biaxially loaded specimens. The focus of the paper is on three-dimensional micro-mechanical numerical analyses of micro-defect-containing representative volume elements covering a wide range of stress states. These calculations lead to more insight in the different damage and failure processes on the micro-scale and their influence on the macroscopic damage laws. With the obtained numerical results it is possible to detect general trends, to propose governing equations for the damage criteria, to develop evolution equations for the damage strains, and to identify constitutive parameters of the anisotropic material model. It is shown that the anisotropic behavior and the loading direction with respect to the principal axes of anisotropy affect the evolution of damage mechanisms on the micro-level as well as the corresponding damage strains.

Automated summary

The paper focuses on numerical analysis of the effect of stress and loading direction on damage and fracture behavior of anisotropic metals. The continuum damage model is enhanced to consider the influence of anisotropy and loading direction on damage criteria and damage strain evolution. Experimental results with uni- and biaxially loaded specimens are used to determine constitutive parameters. Micro-mechanical numerical analyses provide insight into damage processes and their influence on macroscopic damage laws. The anisotropic behavior and loading direction affect damage mechanisms and damage strains on the micro-level.