Experimental study on the cumulative damage constitutive model of high-performance steel Q345GJ under cyclic loading

Abstract GJ series steel is a new type of high-performance structural steel, which has emerged in China steel construction, and it has been widely utilized in steel-framed building structures. To investigate the low cycle fatigue performance and cumulative damage behaviors and find a suitable constitutive relationship of GJ series steel under cyclic loading, a total of eighteen Q345GJ steel low cycle fatigue experiments have been carried out. The mechanical behavior of Q345GJ steel were discussed, including monotonic loading behavior, hysteresis loading behaviors and energy dissipation capacity. Based on the cyclic behavior of GJ series steel, a modified cumulative damage model was recommended. Then, with comparison of the Q345GJ tests data (including the data in public papers) under various loading systems, the model proposed in this paper is proved correct and can be used to simulate the cyclic behavior of Q345GJ members.