A PROBABILISTIC APPROACH FOR MODELLING OF FRACTURE IN MAGNESIUM DIE-CASTINGS

Abstract

Quasi-static tensile tests with specimens cut from a generic cast component are performed to characterise the mechanical behaviour of the high-pressure die cast)magnesium alloy AM60. The experimental data is used to establish a probabilistic methodology for finite element modelling of thin-walled die castings subjected to quasi-static loading, The cast magnesium alloy AM60 is described using an elastic-plastic constitutive model consisting of a high-exponent, isotropic yield criterion, the associated flow law? and all isotropic hardening rule. A novel probabilistic approach for modelling of fracture In thin-walled magnesium die-castings using finite element analysis is developed. The Cockcroft-Latham criterion for ductile fracture is adopted with the fracture parameter assumed to follow a modified weakest link Weibull distribution. Comparison between the experimental and predicted behaviour of the cast magnesium tensile specimens gives very promising results.