Experimental study of fatigue damage of glass-fiber reinforced aluminum laminates (FMLs)

According to domestic and foreign standards and references, fatigue experimental samples of glass-fiber reinforced aluminum laminates (FMLs) were designed according to its features, and constant amplitude tension-tension fatigue experiments were performed under different fatigue loads. During testing, cracks appeared firstly on the surface aluminum layers and then many cracks were found on the surfaces. With cycles increasing, cracks grew and then the delamination developed fast until samples were broken completely. Fatigue initiation life and crack growth life of FMLs were measured and compared and their features were given. S-N curves of FMLs and CCF300 with the same thickness were obtained and compared. Fatigue life of each FML changes slowly with loads and almost seems to be logarithmic function line. When the load is higher than 400 MPa, FML has the same level fatigue life as CCF300, while its fatigue life is much lower than CCF300 if the load is smaller than 300MPa. All these provide, we believe, information useful to aircraft designers.