Tensile and Fatigue Properties of T700/QY8911 Stitched Composite Laminates

The static tensile test and tension-tension fatigue test of T700/QY8911 stitched composite laminate were conducted, and the tensile and fatigue property of ply ［0/90］4s and ［0/45/90/-45］2s composite laminates at different stitching orientations were studied. The finite element model of T700/QY8911 stitched composite laminate was established to simulate the elastic modulus. The results show that stitching can significantly improve anti-delamination property of the composite laminates, and the stitched composite laminates under static tensile load showed the characteristics of linear elastic material. The stitched composite laminate had subsequent carrying capacity when the peak load was reached, while the carrying capacity of non-stitched laminates consecutively declined until final destruction. The stiffness degradation curves of stitched composite laminates under the tension-tension fatigue load presented the characteristics of three stages function features. The finite element calculated results of the longitudinal elastic modulus of the stitched composite laminate agreed well with the experimental results, which confirmed the validity of the model.