An Anisotropic Hardening Rule for Elastoplastic Solids Based on Experimental Observations

Abstract

A hardening rule is described based on yield and memory surfaces. A memory surface indicates the extent of loading, and a yield surface is the locus of the elastic region. We define a hardening modulus curve which relates the change in size of the yield and memory surfaces to the tangent modulus of the material at the maximum load. The evolution of the yield surface is described for both the proportional and nonproportional loading paths. Both quasi-static and stable cyclic loading is considered. An attractive feature of this nonlinear hardening law is that the material constants associated with it are limited—three in all—and they can be easily determined from a simple test. The predictions of the proposed hardening law are compared with the experimental data for proportional and nonproportional loading paths, and are found to be in good agreement.