缝纫对复合材料层合板强度和抗冲击性能的影响

 主要研究了缝纫对复合材料层合板的强度和抗冲击性能的影响。通过对不同缝纫密度、缝纫方向、缝线材料和缝线直径的试件进行试验研究 ,分析了缝纫参数对层合板的压缩强度、层间剪切强度、断裂韧性 GIC和 GIIC、低速冲击损伤以及冲击后压缩 ( CAI)强度的影响。结果表明 :缝纫使层合板的 GIC和 GIIC有明显提高 ;随缝纫密度的增大 ,层间剪切强度和 CAI强度有显著提高 ,冲击分层损伤面积有一定程度的减小 ;但它们与缝线的直径关系不大。

EFFECTS OF STITCHING ON STRENGTH AND IMPACT DAMAGE RESISTANCE OF COMPOSITE LAMINATES

Stitching can improve the delamination resistance of traditional 2D laminates obviously. However, it may result in the degradation of other mechanical properties due to the creation of resin pockets or the breakage of in plane fibers. In this paper, the effects of through the thickness stitching on compression strength, interlaminar shear strength, Mode I and Mode II fracture toughness, impact damage resistance of composite laminates and compression after impact (CAI) strength were investigated experimentally. Specimens with varying stitching density, stitching direction, thread type and thread diameter are studied. The results show that stitching significantly improves G IC  and G IIC  of laminates; with increase in stitching density, interlaminar shear strength and CAI strength increase rapidly, and the impact damage area decreases slightly; however, they are not closely related to the thread diameter. In addition, the mechanisms by which stitching increases the CAI strength and fracture toughness were discussed.