Random fatigue life prediction of carbon fibre-reinforced composite laminate based on hybrid time-frequency domain method

Abstract

To evaluate fatigue life of composite laminate with hole under random loading, a random fatigue life prediction model is established by hybrid time-frequency domain method in this paper. Firstly, dynamic response of composite laminate is obtained from FE model in frequency domain. Secondly, root mean square of stress of six stress components of critical damage point in frequency domain are transferred to stresses in time domain. At last, 3D Tsai-Hill static failure criterion is adopted to convert the multiaxial stress into the uniaxial equivalent stress. Fatigue life is predicted by equivalent stress fatigue life code. The method is validated with the random vibration fatigue test of carbon fibre-reinforced composite laminate. Numerical results are compared with random fatigue experiments which show good agreement with numerical results.

Novel 2D strain-rate-dependent lamina-based and RVE/phase-based progressive fatigue damage criteria for randomly loaded multi-layer fiber-reinforced composites

“…Some researchers have stated that almost no indications of the elastic moduli degradation may be noted for the fibers and the small stiffness degradation of the resin matrix mainly happens in the last 20-30 percent or even, the last cycles [16] of the fatigue life. Some researchers considered no degradation in the material properties but showed excellent agreement with the experimental results [3,25,26]. Some others have claimed that due to the huge scatter in test data, it seems meaningless to predict the residual strength degradation or degradation in the material properties, especially when the fiber breakage is the dominant fracture mode [4].…”