Long fiber reinforced polyamide and polycarbonate composites. II: Fatigue behavior and morphological property

[[abstract]]Fatigue behavior and morphology of long glass fiber reinforced semicrystalline polyamide (nylon 6,6) and amorphous polycarbonate (PC) composites were investigated. The fiber length distribution in the molded samples was calculated by image analyzer. The tension-tension fatigue loading tests at various levels of stress amplitudes were studied. The two-parameter Weibull distribution function were applied to obtain the statistical probability distribution of experimental data. A good correlation existed between the experimental data and the Weibull distribution curves. Straight line SN curves of long glass fiber reinforced semicrystalline polyamide and amorphous polycarbonate composites at various probabilities were established. The stiffness of the composite under tension-tension fatigue loading was measured. The thermal stress history was also investigated by thermo-imaging techniques during fatigue life testing. Further, failure morphology was examined by scanning electron microscopy (SEM). The results showed that the fracture behavior of the ductile damage in polyamide is different from the brittle damage in polycarbonate.[[fileno]]2020332010033[[department]]材料