Self-heating Method for Fatigue Limit Determination on Thermoplastic Composites

To achieve weight reduction of structures, composite carbone fabric materials are used extensively in different industrial applications as aerospace and automotive. Their high mechanical performances and good fatigue durability offer advantages compared to more traditional metallic materials. To be able to design composite parts, it is necessary to characterize their fatigue behavior and specifically to evaluate fatigue limites. All fatigue tests generally used for this determination are time-consuming and potentially highly costly.We propose herein after to apply on woven carbon fibres thermoplastic matrix composites, the self-heating method, which has been developed and validated initially on unidirectional carbon/epoxy composite laminates.The material under consideration is a balanced woven made of carbon fibers and PA66 matrix. Static and fatigue tests are conducted on two stacking sequences ([0°] and [+/-45°]) in order to identify their mechanical properties. Our findings demonstrate that during self-heating tests at room temperature, the mechanisms leading to the increase in temperature are different compared with those observed in thermoset matrix composite systems. Anew analysis of these results is mandatory to obtain the limit of fatigue. The fatigue limit obtained within hours, in our work appears comparable with the results obtained with the classical SN curves method.