三维编织复合材料缝合连接设计及破坏机制

 针对三维编织复合材料的缝合连接设计问题,在研究制造工艺基础上,建立缝合连接的强度校核和参数设计公式,绘制连接部件的内力响应。对不同搭接长度和缝合密度的三维编织缝合连接复合材料试件进行拉伸试验,发现缝合连接接头主要发生3种形式的破坏:在搭接的一端或两端整体断裂;搭接缝合区分层断裂;缝合区中部分分层、部分整体断裂。机制分析表明,断裂模式主要受缝合参数的影响,也与内力分配和是否存在应力集中有关,实际应用中可以根据情况采用不同的连接形式。

Design and destroying mechanism of stitching joint 3-D braided composites

Targeting at the design of the jointing of 3-D braided composites,a strength proof and parameter design formula were established and internal force response of the joint part was drawn based on studies of manufacture process.Tensile tests were conducted on 3-D stitching joint braided composites with different overlap lengths and stitching densities.The results showed that there are 3 patterns of fracture,namely,broken at one or two ends of the overlap area;delaminated in the stitching part;broken as well as delaminated in the stitching section.Analysis of destroying mechanisms indicated that the fracture mode is determined by stitching parameters,also related to the internal force distribution and stress concentration.The joint modes can be designed flexibly for actual loading conditions.