On Factors Affecting Localization and Void Growth in Ductile Metals: A Parametric Study

A large number of factors besides void volume fraction are known to play significant roles in influencing void growth and strain localization. In spite of this, macroscale constitutive models currently available in the literature account for only a few of these factors while describing the evolution for damage, or porosity, in ductile metals. The absence of other contributing factors from the models could be attributed to the fact that past investigations have considered only a few (at most three) while determining their overall influences on void growth and strain localization. The present study seeks to examine the sensitivities exerted by a list of seven independent parameters on strain localization and void growth in Aluminum 1100 and 304 L Stainless Steel by performing a series of parametric calculations using the finite element method. Owing to the wide range of parameters, an optimal matrix of finite element calculations is generated using the statistical method of design of experiments (DOE). The DOE method is also used to screen the finite element results and yield the desired parametric influences as outputs. As far as localization and void growth are concerned, it is observed that, while temperature and microporosity exerted the most dominant influences, pre-strain effects and geometric parameters, such as uniformity as pore size, and the shape and distribution of pores, are noted to play significant secondary influences.