MECHANICAL PROPERTY AND CONSTITUTIVE MODELING OF LOW YIELD POINT STEELS
Yang GAO 1*, Gang SHI 1, Xun WANG 2 and Yong ZHANG 3
1 Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry, Department of Civil Engineering, Tsinghua University, Beijing, China
2 East China Architectural Design & Research Institute Co., Ltd, Shanghai, China
3 School of Civil Engineering, Beijing JiaoTong University, Beijing, China
Equipped with many advantages, such as low yield point, low yield-to-ultimate strength ratio, good ductility, and excellent energy dissipation capacity, low yield point (LYP) steels have been developed and adopted as new high performance structural steels in seismic application. This paper presents the research works on the mechanical properties and constitutive models of LYP steels fabricated in China, namely LY100, LY160, and LY225. Axial steel coupons machined from LYP steels were tested experimentally under monotonic and different cyclic loading patterns. In order to comprehensively describe the possible loading conditions in engineering application, 12 different cyclic loading patterns have been elaborately designed to investigate the material cyclic responses. Through test results, the monotonic and hysteretic properties were analyzed. Then, the material parameters for LYP steels of two constitutive models (the Chaboche model and the Hu et al. model) were calibrated based on the experimental data. Those two constitutive models were then implemented in the general purpose finite element software Abaqus. The accuracy and applicability of those two constitutive models were verified by comparing the test results and simulations. Finally, a comparative analysis was performed between those two models. The results show that LYP steel is a promising structural material for seismic design and also provide the findings of its material properties and simulation method.
Low yield point steel; Mechanical property; Constitutive model