A theory of viscoplasticity based on infinitesimal total strain

摘要: A viscoplasticity theory based upon a nonlinear viscoelastic solid, linear in the rates of strain and stress tensors but tensor infinitesimal tensor, is being investigated for isothermal, homogeneous motions. general anisotropic form specific isotropic formulation are proposed. yield condition not part transition from (elastic) to (inelastic) behavior continuous. Only total strains used constant volume hypothesis employed. In this paper Poisson's ratio assumed be constant. The proposed equation can represent: initial elastic behavior; response torsion (tension) after arbitrary prestrain (prestress) tension (torsion); pure hydrostatic loading; slope large instantaneous changes rate; (strain)-rate sensitivity; creep relaxation; defined limit very slow fast loading. Stress-strain curves obtained at different loading will ultimately have same “slope” their spacing nonlinearly related rate. above properties by qualitative arguments on characteristics solutions resulting first-order differential equations. some instances numerical examples given. For metals isotropy we propose simple whose coefficient functions determined tensile test [Eqs. (31), (35), (37), (38)]. Specializations suitable materials other than possible. shows that model represent essential features metal deformation reaffirms our previous assertion basically rate-dependent represented piecewise viscoelasticity. cyclic must modified account history dependence sense plasticity.