Effect of Washer Size and Tightening Torque on Bearing Performance of Basalt Fiber Composite Bolted Joints

ABSTRACT

The effect of tightening torque and washer size on the performance of basalt natural fiber composite joints was investigated experimentally. It was found that washer size is the main design driver in controlling the out-of-plane behavior of the joint. Specifically, there was a 36.5% increase in the 0.2% offset strength when the torque was increased for small washer configurations, whereas a 42% increase was observed when the torque was increased for large washer configurations. Moreover, the ultimate bearing strength also showed an improvement under the combined effect of washer size and tightening torque. Additionally, damage onset and failure mechanisms of the bolted joint were investigated using optical microscopy. The morphological observations indicated excessive crushing for large washer configurations. It is postulated that bearing performance could be improved by choosing appropriate washer size and tightening torque.

摘要

实验研究了拧紧力矩和垫圈尺寸对玄武岩天然纤维复合材料接头性能的影响. 发现垫圈尺寸是控制接头平面外行为的主要设计因素. 具体来说，当小垫圈配置的扭矩增加时，0.2%的偏移强度增加了36.5%，而当大垫圈配置的扭矩增加时，观察到42%的增加. 此外，在垫圈尺寸和拧紧力矩的共同作用下，极限承载力也有所提高. 此外，利用光学显微镜研究了螺栓连接的损伤起始和失效机理. 形态学观察表明，大垫圈结构的挤压过度. 通过选择合适的垫圈尺寸和拧紧力矩，可以提高轴承的性能.

KEYWORDS:

• Out-of-plane deformation
• bearing strength
• natural fiber composites
• bolted joints
• failure morphology
• failure mechanism

关键词:

• 平面外变形
• 承载强度
• 天然纤维复合材料
• 螺栓连接
• 破坏形态
• 失效机理

Acknowledgments

The authors would like to acknowledge the financial support provided by Universiti Teknologi PETRONAS. Moreover, the authors would like to acknowledge the support of Prof Dr Faiz Ahmad, Professor at Universiti Teknologi PETRONAS.

Conflicts of interests

The authors declare no conflict of interest with respect to the research or publication of this work.

Additional information

Funding

This work was supported by the Yayasan Universiti Teknologi PETRONAS (YUTP) [015LC0-250].