Abstract：At present, the research on low cycle fatigue of low-yield-point steel LYP225 was rarely mentioned. To better investigate the properties and behavior of low-yield-point steel, experiments of two groups of different dimensions of specimens were carry out. All of the specimens were tested under monotonic loading and cyclic loading. This paper presented the results, like the skeleton curve, hysteresis loops, low cycle fatigue life and so on. The influence of slenderness ratio on the fatigue life of low-yield-point steel was also discussed. To simulate the skeleton curves, Ramberg-Osgood model was applied. Moreover, the low cyclic fatigue life (S-N) curves were based on Coffin-Manson model. The combined hardening parameters, extracted from the experimental data, were input in the finite element models, whose simulation results agreed well with the experimental hysteretic curves. The results showed that Chinese LYP225 has plumper hysteresis loops and better ductility and fatigue properties than the foreign steel in the same dimension and grade. Chinese LYP225 is more sensitive to the impact of slenderness ratio. Under the same strain amplitude, the low cycle fatigue life became shorter with higher slenderness ratio. The calibrated hardening parameters based on the test data can be further used in the seismic analysis of structural members.
