Abstract

In a previous research investigation, using the Mróz model and the endochronic theory of plasticity as their bases, two sets of elastic-plastic constitutive relations were identified that account for the interaction in stress fields between adjacent particles in particulate metal matrix composites (PMMCs). In this paper the ability of the two models to predict the behavior of PMMCs under variable amplitude nonproportional cyclic loading paths is evaluated by comparing the models predictions with experimental results obtained from a series of biaxial (tension-torsion) cyclic tests performed on tubular specimens made from 6061-T6 aluminum with 10 and 20% volume fractions of alumina particles. For most of the investigated loading paths, both models predict satisfactorily the amplitudes of the experimental strains. However, the endochronic theory-based constitutive model generally gives better predictions of the measured strains.

Keywords

cyclic plasticity, nonproportional loading, particulate reinforced material, Mróz model, endochronic theory

Authors