Low-Cycle Fatigue Crack Propagation Behavior of Cracked Steel Plates Considering Accumulative Plastic Strain

AH-32 steel has been widely used in ship and marine structures but not been extensively studied for low-cycle fatigue (LCF) crack growth characteristics. The objective here is to explore the evolution mechanism behind LCF crack propagation behavior under different load conditions, for which the investigation of experimental and numerical simulation is considered in a detailed manner. An analytical model is presented to consider the effect accumulative plastic strain for ship cracked plate subjected to high stress cyclic loading. Different numerical parameters are proposed to quantify stress–strain field near crack-tip, and an integral model is developed to calculate the magnitude of the compressive stress. The effect of the maximum and minimum load on crack closure level is analyzed. The results show that there is an excellent correlation between LCF crack closure parameter and the magnitude of the compressive stress in the plastic wake, which indicates the presented integral model provides a new way for LCF crack propagation analysis.