The fatigue damage mesomodel for fiber-reinforced polymer composite lamina

This study deals with the modeling of the behavior of fiber-reinforced composite laminas under fatigue loading. On the basis of continuum damage mechanics, the non-linear cumulative damage model is developed and established on the mesoscale of the elementary layer. Three damage failures are taken into account: brittle behavior in the fiber direction, elastoplastic damage behavior under shear and transverse tension stress. Meanwhile, the couple effect of damage anisotropy between transverse and shear directions in-plane is considered. The failure criterion is presented and proved as an accurate approach to predict fatigue life of composite unidirectional lamina. The results of the fatigue damage model are obtained by a numerical simulation method, and the step value of cyclic iteration is discussed to acquire the predictive life range. Finally, the results of prediction agree well with the relative experimental data.