Abstract
A rigorous method for the analysis of plastic bifurcation under in-plane stress was presented in order to precisely assess the localization of plastic buckling patterns of plates structures. In this analysis, two kinds of constitutive models, i. e. bi-linear model and two-surface model, respectively, within the framework of J2 flow theory, were considered to investigate the effect of constitutive relations. By using this method, it was examined how the localization behavior is influenced by the localized initial deflections. Based on this result, we discussed the validity of the approximate method proposed by Tvergaard and Needleman where a small localized initial deflection was given to analyze the localization phenomenon without carrying out the plastic bifurcation analysis.
