Mechanical properties of low yield point steels subjected to low-cycle structural damage

Abstract

This paper focuses on the effects of prior cyclic loading on the subsequent monotonic tensile properties of low yield point (LYP) steels compared to that of virgin material. Carefully designed axial steel coupons machined from LYP steel plates were tested under various cyclic loading protocols to model seismic-induced damage and then monotonically tensioned until fracture to obtain their remaining mechanical properties. The experimental results indicate that a prior history of cyclic loading caused an increase in strength but a decrease in both ductility and stiffness of LYP steels. Moreover, significant cyclic hardening was observed in LYP steels, which could be characterized as combined isotropic and kinematic hardening, of which the former component played an overwhelmingly dominant role.