缝合复合材料层板面内边缘冲击及冲击后压缩实验

Experimental Investigation of Stitched Composite Laminates Subjected to In-plane Edge Impact and Compression After Impact

利用真空辅助树脂传递成型(VARTM)技术制备缝合/未缝合碳纤维层板,并分别对其进行了五种不同能量的面内边缘冲击及冲击后压缩实验,结构内部的冲击损伤通过超声C扫描检测技术进行观测。结果表明:缝合工艺的引入能有效提高碳纤维层板的面内冲击阻抗及损伤容限,在五种能量范围内,冲击峰值力的增幅达到4.54%~10.33%,冲击后剩余压缩强度的增幅最高达到9.32%;另外,通过超声C扫描检测结果发现,面内边缘冲击后,在复合材料面板上的冲击点附近会出现一个半椭圆形的分层区域,且缝合层板的分层损伤面积明显小于未缝合层板;未缝合层板面内边缘冲击后压缩的主要破坏模式为分层扩展,而缝合层板面内边缘冲击后的压缩失效模式为整体屈曲。

Stitched and unstitched carbon fiber reinforcedplastic(CFRP) laminates were manufactured by the vacuum assisted resin transfer molding(VARTM) technique and subjected to in-plane edge impact and compression after impact under five different energies. The damage after edge impact inside the structure was detected by the ultrasonic C-scan method. The experimental results show that stitching can improve the edge-impact resistance and damage tolerance of the laminates effectively. Within the impact energy range tested, the peak impact force increased by 4.54%~10.33% and the maximum increase of the residual compressive strength after impact was 9.32%. In addition, through the result from ultrasonic C-scan, it is found that there was a semi-elliptical delaminated damage area near the impact edge on the composite plates after in-plane edge impact of the structures, and the damage area of the stitched laminates was significantly smaller than that of unstitched. The main compression failure mode after in-plane edge impact of the unstitched laminates was delamination propagation, while the stitched laminates was global buckling.