Experimental Verification of Constitutive Equations for Plasticity under Biaxial, Cyclic and Nonradial Loading Conditions

摘要

The plasticity of austenitic steel WN 1.4948 and ferritic steel WN 1.6770 at room temperature was studied to obtain constitutive equations for plastic deformations arising from arbitrary loading histories. Plastic deformation is described by the fraction model. Since austenitic steel shows considerable strain rate effects at room temperature it was necessary to extend the description with viscoplasticity. The mathematical description was verified for biaxial states of stress. Loading programs with monotonically increasing loading conditions, as well as cyclic and nonradial loading histories were considered. The ratio between experimental results and theoretical predictions is satisfactory.