Some theoretical considerations and experimental investigations on a constitutive law in thermoplasticity (Q1093428)

Based on classical thermodynamics and restricted to classical continua, a general frame for the formulation of constitutive laws in thermoplasticity is sketched. Within this frame a more particular constitutive law is formulated taking into account large nonisothermal deformations with isotropic and anisotropic (kinematic) hardening, and allowing for certain deviations from the so-called normality rule. The material parameters and functions entering this law are determined for a mild carbon steel by isothermal tension-torsion tests on thin-walled tubes at different temperature levels. The separate knowledge of the influence of deformation rate is investigated since processes with large deformations at higher rates usually are nonisothermal. With respect to cyclic deformations, the given constitutive law has to be generalized.