Progressive fatigue behavior of single-lap bolted laminates under different tightening torque magnitudes
Progressive fatigue behavior of single-lap bolted laminates under different tightening torque magnitudes
复制标题
DOI：
10.1177/1464420720936723
复制
发表时间：
2020-06
期刊：
影响因子：
--
通讯作者：
M. Feyzi;S. Hassanifard;A. Varvani-Farahani
中科院分区：
文献类型：
--
作者：
M. Feyzi;S. Hassanifard;A. Varvani-Farahani
本文研究了单搭接螺栓连接件在单轴载荷循环下，不同扭矩大小下的疲劳损伤和寿命。被粘体由E-玻璃/环氧树脂层使用手工铺层技术构造，并通过1.5、3和8 Nm的施加扭矩组装。增加扭矩有利于提高接头的最终疲劳寿命，8 Nm拧紧接头的高周疲劳寿命是1.5Nm拧紧接头的10倍。在本研究的数值部分中，采用三维有限元分析，并将施加扭矩的影响纳入渐进损伤模型中，以评估螺栓接头的损伤和失效。对于较高扭矩水平拧紧的接头，数值结果显示较高的疲劳寿命，但在孔附近的更多分层的成本。通过扫描电子显微镜研究了层合板的断裂表面，发现随着复合材料接头的疲劳循环，在基体、纤维和基体-纤维界面上出现了更多的裂纹/损伤。试验接头的实验寿命数据与通过使用有限元分析表明开发的模型作为一个适当的工具，在评估施加的扭矩对螺栓层压板的疲劳断裂行为的影响预期同意。
The present paper studies fatigue damage and life of single-lap bolted joints tightened with different torque magnitudes subjected to uniaxial load cycles. The adherends were constructed from E-glass/epoxy layers using a hand layup technique and assembled by 1.5, 3, and 8 N m of applied torques. Increasing the torque magnitude benefitted the final fatigue life of the joints so that the high-cycle fatigue life of the joint sample tightened with 8 N m was as high as 10 times that of the joint tightened with 1.5 N m. In the numerical section of this study, a three-dimensional finite element analysis was employed, and the impacts of applied torques were included in the progressive damage model to assess damage and failure in the bolted joints. For the joints tightened with higher torque levels, numerical results revealed higher fatigue lives but at the cost of more delamination at the vicinity of the hole. Laminate fracture surface was investigated through scanning electron microscopy and more cracking/damage progress was evidenced in matrix, fiber, and matrix–fiber interface as composite joints experienced fatigue cycles. Experimental life data of tested joints agreed with those anticipated through the use of finite element analyses indicating the developed model as an appropriate tool in evaluating the effects of applied torques on the fatigue fracture behavior of bolted laminates.