Constitutive description for casting magnesium alloyinvolving void evolution
(1. College of Resources and Environmental Science, Chongqing University, Chongqing 400044, China;
2. Key Laboratory for Exploitation of Southwest Resources and Environmental Disaster Control Engineering, Ministry of Education, Chongqing University, Chongqing 400044, China)
2. Key Laboratory for Exploitation of Southwest Resources and Environmental Disaster Control Engineering, Ministry of Education, Chongqing University, Chongqing 400044, China)
Abstract: In order to investigate the effect of microvoids on the mechanical behavior of casting magnesium alloy, a spherical void−cell model of the material was presented. The velocity and strain fields of the model were obtained from the assumption that the material matrix is homogeneous and incompressible. The hardening and softening functions, which respectively reflect the deformation-hardening and void-softening behaviors of the material, were presented and introduced to an endochronic constitutive equation for describing the mechanical behavior of the material including microvoids. The corresponding numerical algorithm and finite element procedure were developed and applied to the analyses of the elastoplastic response and the porosity of casting magnesium alloy ZL102. The computed results show satisfactory agreement with experimental data.
Key words: casting magnesium alloy; spherical void; void volume fraction; elastoplasticity; constitutive model