A parametric finite element study and an analytical model of particle distributions on post-necking deformation and failure mode in AA5754 aluminum alloy sheets

Finite element analysis of a simplified large particle field, edge constrained plane strain model is used for parametric studies of the influence of particle distributions on post-necking deformation and failure mode in AA5754 aluminum sheets. The models show that the post-necking deformation decreases with volume fraction of particles and fraction of stringers, and increases with interparticle spacing. It is to be noted that a stringer is a string of second phase particles that is frequently observed in continuous strip cast (CC) sheet aluminum alloys. The post-necking deformation initially decreases with the length of stringers, but after a critical stringer length, it increases. An analytical model to estimate the number of stringers which act as initial active damage sources is able to predict a critical stringer length for least post-necking deformation and can serve as a design tool.