Numerical study on high-cycle fatigue crack growth of sinusoidal interface based on cyclic cohesive zone model

Abstract

The numerical study of the high-cycle fatigue crack growth for the double cantilever beam (DCB) specimen with sinusoidal interface under remote mode-I loading is carried out based on the discrete interface element and the cyclic cohesive zone model (CCZM). Compared with the continuous cohesive element, this discrete interface element is more suitable for complex interface, easier to implement, and has better computational convergence. According to the summarized laws by the systematic researches, the general process of calibrating CCZM is proposed. The accuracy of proposed method is verified by the benchmark models representing different modes fatigue crack. In the simulation results of fatigue crack growth for sinusoidal DCB specimens, the as-N (as is the crack growth length and N is the number of load cycles) curves exhibit periodic oscillation behavior. The constructed rate model indicates that, the oscillation behavior intensifies with the increase of aspect ratio A/λ (A = amplitude, λ = wavelength). Moreover, the sinusoidal interface can delay fatigue crack growth, and this effect is more obvious with the increase of interface roughness. Due to the stress concentration at the wave crests and troughs of sinusoidal interface, the fatigue damage is easier to accumulate, which is the mechanism of fast and slow alternating propagation. In addition, the results of this paper also demonstrate that, the periodic oscillation behavior will be more intense when the materials on both sides of interface are inconsistent.