ABSTRACT
Stainless steel does not require painting and can contribute to the reduction of life cycle costs of structures. In general, material constitutive laws are essential to accurately evaluate the seismic behavior of structures in numerical analysis. In this study, the yield surface and flow rule of stainless steel were experimentally investigated to establish the multiaxial constitutive law. Axial forces and torques were applied to cylindrical specimens to represent various stress states. The yield surface of stainless steel in the plane of axial and shear stress were determined, and the evolution of plastic strain after yielding was observed. It was shown that austenitic grades exhibited isotropic yield surfaces, while duplex ones exhibited elliptical ones with an eccentricity of 0.7. It was also confirmed that the standard deviation of the direction of plastic strain propagation from the theoretical value is about 10 degrees, and the associated flow rule could be applied.
