Study of low-cycle fatigue crack growth behavior of central-cracked stiffened plates

Abstract

This work is aims to study the low-cycle fatigue (LCF) crack growth behavior of central-cracked stiffened plates through experimental and numerical analysis methods. A central-cracked stiffened plate with two stiffeners is manufactured to test the influence of the stiffeners on the crack propagation in the base plate. The effects of loading amplitude, the stiffeners’ size and location on the crack growth life are investigated in the test. In numerical analysis, an elastic-plastic numerical model is developed to simulate the crack propagation of stiffened plates considering the influence of the plasticity-induced crack closure (PICC). The results show that PICC and the crack opening load can clearly reflect the crack arrest performance of the stiffener on the crack propagation in the plate. Increasing the stiffener stiffness or decreasing the space between the two stiffeners is beneficial to reduce the driving force acting on the crack tip, prolonging the crack growth life. This work is intended to contribute to a better understanding of the crack arrest performance of stiffened plates through the crack closure mechanism.