Low cycle fatigue property and fracture behavior of low yield point steels

For seismic control and isolation techniques, low yield point steels are among the most reliable and ideal energy-dissipating materials. Structures under earthquake conditions are usually subjected to cyclic loads with large strain amplitudes, where excellent low cycle fatigue and fracture performance under repeated loading is an essential requirement. In the study presented in this paper, comprehensive and systematic investigation was conducted on the low cycle fatigue properties and fracture behaviors of low yield point steels (LY100, LY160, and LY225). Axial steel coupons were tested under different constant strain amplitudes ranging from 0.5% to 6% with increments of 0.5%. Following introduction of the experimental details, observations and fatigue life are reported. Then, based on the experimental data, the cyclic hardening behavior and the cyclic stress-strain response are thoroughly analyzed. Finally, with the aim of predicting the low cycle fatigue life, the material parameters of the Coffin-Manson relationship and Kuroda model are determined and comparative analyses are performed. This paper may provide a valuable reference for engineering applications and further research into the low cycle fatigue performance of low yield point steels.