A modified failure envelope method for failure prediction of multi-bolt composite joints
A modified failure envelope method for failure prediction of multi-bolt composite joints
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DOI：
10.1016/j.compscitech.2013.04.018
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发表时间：
2013-06-28
影响因子：
9.1
通讯作者：
Fei, Binjun
中科院分区：
文献类型：
--
作者：
Liu, Fengrui;Zhao, Libin;Fei, Binjun
本文在Hart-Smith提出的传统失效包络线法的基础上，通过大量的开孔层合板、双搭接单螺栓和多螺栓连接的准各向同性或近准各向同性铺层的强度试验，提出了一种修正的失效包络线法，用于预测多螺栓连接的最终失效模式和强度。与传统失效包络线法中的轴承“截止”不同，改进后的包络线法考虑了旁路载荷对轴承失效的影响，提出了一种新的由两条斜线组成的包络线。它可以通过附加的层合板压缩强度试验以及对开孔层合板和开孔层合板的半解析或数值分析，结合点应力准则来建立。给出了改进的失效包络线法与结构失效分析过程的集成流程图。进行了一系列试验，以提供基本参数和有限元分析进行了修改后的失效包络线。提出的方法被应用到两个螺栓和四个螺栓的碳-碳双搭接接头与近准各向同性铺层。将该方法和传统方法的预测结果与试验数据进行了比较。结果表明，该方法能有效地预测双搭接复合材料螺栓连接的失效模式，并能获得更准确的极限载荷。(C)2013爱思唯尔有限公司保留所有权利。
This paper presents a modified failure envelope to predict final failure mode and strength of multi-bolt composite joints based on the conventional failure envelope method, which was presented by Hart-Smith from abundant strength tests of open hole laminates, double-lap single and multi-bolt joints with quasi-isotropic or near-quasi-isotropic lay-ups. In contrast to the bearing "cutoff" of conventional failure envelope method, the modified one takes into account the effect of bypass load on the bearing failure and a new polyline consisted of two oblique lines is proposed. It is able to be established by an additional compressive strength test of laminates and semi-analytical or numerical analysis of fastener-hole laminates and open-hole laminates, combined with the point stress criterion. A flowchart of integration structure failure analysis process with the modified failure envelope method is provided. Series of tests were carried out to provide basic parameters and finite element analysis was conducted for the modified failure envelope. The method proposed was applied to two-bolt and four-bolt carbon-to-carbon double-lap joints with near-quasi-isotropic lay-ups. The predictions of the method proposed and the conventional one were compared with the tests data. The results indicate that the method proposed can obtain effective prediction of failure modes, and more accurate ultimate failure loads in double-lap composite bolted joints. (C) 2013 Elsevier Ltd. All rights reserved.