Progressive failure prediction of pinned joint in quasi-isotropic laminates used in pipelines

Abstract To simulate the progressive failure of pinned joint in quasi-isotropic [0/45/-45/90]s glass fiber reinforced polymer (GFRP) composite laminates used in pipeline, 3-D finite element model is employed in the present work. Hashin failure criterion as a progressive damage model associated with Virtual-Crack-Closing-Technique (VCCT) delamination model has been adopted to predicate the failure due to fiber breakage, matrix cracking and delamination in composite pinned joint. This technique may be an innovation for this paper. W/D has been changed to get different modes of failure, i.e. tension, shear-out and bearing failures, in composite pinned joint,. The failure mode for GFRP composite pinned joint has been predicted finally after prediction the failure at each ply laminate of stacking sequence [0/45/-45/90]s. An experimental work of pinned joint in quasi-isotropic GFRP composite laminates has been conducted to validate the present numerical results. The numerical and experimental results showed an agreement between them. Therefore, the present 3D finite element model can be considered as a good candidate to expect the progressive damage in composite pinned joints.

摘要：为模拟管道用准各向同性[0/45/-45/90]s铺层玻璃纤维增强聚合物（GFRP）复合材料层合板销钉连接的渐进失效过程，本文采用三维有限元模型开展研究。本文采用结合虚拟裂纹闭合技术（Virtual-Crack-Closing-Technique，VCCT）分层模型的Hashin失效准则（Hashin failure criterion）作为渐进损伤模型，用以预测复合材料销钉连接中的纤维断裂、基体开裂与分层失效，该方法可视为本文的一项创新。通过调整W/D以获得复合材料销钉连接的三种典型失效模式，即拉伸失效、剪切脱出失效与挤压失效。在对[0/45/-45/90]s铺层顺序的各单层板逐一完成失效预测后，最终得到GFRP复合材料销钉连接的失效模式。本文开展了准各向同性GFRP复合材料层合板销钉连接的试验研究，以验证本文数值模拟结果的合理性。数值结果与试验结果吻合良好，因此本文所构建的三维有限元模型可作为预测复合材料销钉连接渐进损伤的有效工具。