Approximate estimation of fatigue strength of polymer matrix composites by material properties

To estimate the fatigue strength (life) of polymer matrix composites (PMC) by material properties, the fatigue process of satin woven carbon fabric laminate composites with two different matrix resins (CF/epoxy, CF/PEEK) was investigated from a microscopic viewpoint and the failure mechanism was discussed in relation to the local stress states and fatigue strength. It was found that fatigue strength can be approximately estimated by the function of material properties, κ. Moreover, it was revealed that the main fatigue damage changes from transverse crack in transverse fiber bundle to fiber fracture in longitudinal fiber bundle in dependence on the value of κ.