Generalized rate-dependent inelastic constitutive equation (the extension of elastoplasticity)

The rate-dependent inelastic constitutive equation is formulated by extending the elastoplastic constitutive equation so as lo retain its mathematical structure and thus reduces to the latter equation at infinitesimal strain rate, whilst the over-stress model, the best-known inelastic constitutive model, has substantially different mathematical structure from the elastoplastic constitutive equation. It belongs to the superposition model pre on the additive decomposition of the inelastic strain rate into the plastic and the creep strain rates. It can describe precisely the rate-dependent inelastic deformation at a wide range of strain rate, whilst the over-stress model cannot predict appropriately the difference of mechanical response due to the rate of deformation, especially inapplicable to the description of deformation at high strain rate.