In the present research, effects of applying strain rate on the mechanical behavior of single-lap glass/CNF/epoxy composite bolted joints including, damage initiation bearing stress, 2% offset bearing strength, ultimate bearing strength, bearing chord stiffness, ultimate bearing strain, and energy absorption were studied. To this end, a comprehensive experimental program was conducted. The protruding head bolt was used, the clearance was considered to be near fit and a finger-tight bolt condition was applied to all joints. The dimensions of joints were chosen to promote the bearing failure mode based on the ASTM standard. Four types of single-lap bolted joints (SLJs) with lay-ups of [–45/0/45/90]s and [90/–452/45]s with and without CNFs were tested at strain rates in the range of 0.0048 s−1 to 0.89 s−1. Unlike the available experimental results, the results obtained by the present experiments showed that the strain rate has a significant effect on all the above-mentioned mechanical parameters of SLJs. Also, it was shown that employing CNFs improved the mechanical parameters of SLJs under quasi-static and dynamic strain rates.

中文翻译：

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应变率对单搭玻璃/碳纳米纤维/环氧树脂复合材料螺栓接头力学性能的影响

在目前的研究中，应用应变率对单搭玻璃/CNF/环氧树脂复合材料螺栓接头力学行为的影响包括损伤起始承载应力、2% 偏置承载强度、极限承载强度、承载弦刚度、极限承载应变, 和能量吸收进行了研究。为此，进行了全面的实验计划。使用了凸头螺栓，间隙被认为是接近配合的，所有接头都采用手紧螺栓条件。选择接头的尺寸以促进基于 ASTM 标准的轴承失效模式。四种类型的单搭接螺栓接头 (SLJ) 与 [–45/0/45/90] s 和 [90/–452/45] s 有和没有 CNF 的铺设在应变率范围内进行了测试0.0048 s-1 到 0.89 s-1。与现有的实验结果不同，本实验获得的结果表明，应变速率对 SLJ 的上述所有力学参数都有显着影响。此外，研究表明，在准静态和动态应变率下，使用 CNF 改善了 SLJ 的机械参数。