A phenomenological framework of constitutive modelling for incompressible and compressible elasto-plastic solids

A unified framework of constructing phenomenological constitutive models fo r a broad class of elasto-plastic materials exhibiting either plastical inc ompressibility (e.g., grey cast iron) or plastical compressibility (e.g., m etal foams) is proposed. The constitutive framework also enables the differ ent yielding behaviours under tension and compression as well as differenti al hardening along different loading paths to be accounted for in a relativ ely simple manner. The resulting plasticity model does not require the diff icult task of experimentally probing the initial yield surface and its subs equent evolution; it is completely determined from a set of as few as two d istinctive stress-strain curves measured along the characteristic loading p aths for isotropic materials. The predicted yielding behaviours for grey ca st iron and metal foams compare favourably with those measured. (C) 2000 El sevier Science Ltd. All rights reserved.