Extension of subloading surface model for accurate prediction of elastoplastic deformation behavior of metals with cyclic softening

Abstract

The subloading surface model has been formulated and applied to the prediction of cyclic loading behavior of metals. However, the existing formulation of this model is limited to metals exhibiting only the cyclic hardening. In the present paper, the material functions prescribing the elastic-plastic transition are extended so as to describe the inverse and reloading behavior and the strain accumulation in cyclic loading more accurately for metals exhibiting not only the cyclic hardening but also the cyclic softening behavior. The experiments on the uniaxial cyclic loading of the seamless steel pipe P110 which exhibits the cyclic softening are performed for the mechanical ratcheting and the constant strain amplitudes. The simulations to the test data are performed by using the same set of material constants. Then, the validity of the extended model for the description of cyclic loading behavior of the seamless steel pipe is verified by comparisons with the test data.

Keywords

• constitutive equation
• elastoplasticity
• subloading surface model
• cyclic hardening/softening
• seamless steel pipe