To study the fatigue life prediction and damage evolution of fiber-reinforced resin matrix composites,the tensile and fatigue tests were conducted on composite laminates.A fatigue life model for fabric laminates was established based on the fatigue data of carbon fiber/epoxy plain woven fabric laminates under four different cyclic stresses.The failure process and degradation of laminates properties were analyzed by using the finite element method,the fatigue life and damage propagation process of fabric laminates were calculated and simulated.The fatigue fracture morphologies and internal damages were observed by using ultrasonic C-scan,ultra-depth microscope,and scanning electron microscope.The fatigue damage evolution and fracture mechanism of fiber-reinforced composite materials were discussed by comparing with the simulation results.The results indicate that the fatigue damage evolution of composite laminates exhibits three obvious stages.In the early stage of fatigue,the in-layer delamination and matrix cracks first appear on both sides of the laminates.The damage propagation accelerates at the middle stage,and the main damage form is the interlayer damage.In the late stage,the delamination is severe in the laminates,cracks tend to be saturated,a large number of fibers fracture,the performances of laminates deteriorate rapidly.Finally,the damages penetrate the entire cross-section and the fatigue fracture occurs.
维普
万方数据