开孔三维编织复合材料的压缩性能

为研究机械开孔对三维编织复合材料压缩性能的影响,测试了2种三维编织复合材料试验件的压缩性能。1种为基本编织(100%编织纱)结构,另1种为含有编织纱/轴向纱(58/42)的结构,试验件编织角约为±12°。根据相关标准要求,分别进行有开孔和无开孔的复合材料试验件准静态压缩试验,并与层合板的压缩性能进行对比。研究结果表明:2种三维编织结构无缺陷材料的压缩强度较为接近,但引入开孔后,无增强纱结构可保留更高比列的压缩强度;引入开孔后,2种三维编织复合材料保留的压缩强度均高于层合板;在失效形式上,2种三维编织复合材料的宏观失效形式较为相似,均为剪切失效,表现出横向断裂且无分层现象。

Compression property of notched 3-D braided composites

In order to study the open-hole notch effect on compression properties of three dimensional (3-D) braided composites, two types of 3-D braided specimens with ±12° braiding angles were fabricated and tested. One was a purely braided structure, and the other was made by incorporating 58% braiding yarns and 42% longitudinal lay-in yarns. According to relevant standards, quasi-static compression tests of composite specimens with and without notch were carried out respectively, and the results of which were compared with that of laminates. The results show that the compression strength of the two types of 3-D braided composites is very similar, but the pure 3-D braided structure with open holes can retain higher proportion of compression strength. Compared with laminated composites, both types of 3-D braided composites retain to show a higher proportion of compression strength. With regard to the failure behavior under compression loading, the two types of 3-D braided composites are also similar, the specimens fail in shear, showing transverse fracture without delamination.