Anti-loosening performance of coatings on fasteners subjected to dynamic shear load
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This paper investigates the self-loosening of threaded fasteners subjected to dynamic shear load. Three kinds of typical coatings, PTFE, MoS2, and TiN applied to bolts and nuts, are tested in this investigation. The study experimentally examines the loosening mechanisms of fasteners and assesses the anti-loosening performance of the three tested coatings based on their tightening characteristics, loosening curves, and the damage of thread surface. Additionally, the anti-loosening performance of the three coatings is compared under different load forms. The results indicate that the PTFE and MoS2 coatings have significant anti-loosening effect, whereas the anti-loosening performance of TiN coating is not satisfactory. It is also found that an appropriate increase of the initial tightening torque can significantly improve the anti-loosening effect. In addition, the microscopic analyses of PTFE and MoS2 coating reveal that a reduced initial tightening torque leads to fretting wear on the thread contact surfaces of fasteners, thereby aggravating the damage.
Keywordsbolted fastener loosening curve fretting coating dynamic shear load
The authors gratefully acknowledge the financial support provided by the National Science Funds for Distinguished Young Scholars (No. 51025519), the Changjiang Scholarships and Innovation Team Development Plan (No. IRT1178), and the Self-Topic Fund of Traction Power State Key Laboratory (No. 2016TPL-Z03).
- Goodier J N, Sweeney R J. Loosening by vibration of threaded fastenings. Mech Eng 67: 794–800 (1945)Google Scholar
- Junker G H. New criteria for self-loosening fasteners under vibration. SAE, Transactions 78: 314–335 (1969)Google Scholar
- Shoji Y, Sawa T. Analytical research on mechanism of bolt loosening due to lateral loads. In ASME Pressure Vessels and Piping Division Conference, Denver, Colorado, USA, 2005.Google Scholar
- Yang G X, Xie J L, Xie Y Y. Study on mechanism of anti-loosening of a new type of nut based on fem. (in Chinese). Engineering mechanics 12: 224–243 (2010)Google Scholar
- Zhang M, Jiang Y, Lee C H. An experimental investigation of the effects of clamped length and loading direction on self-loosening of bolted joints. Journal of Pressure Vessel Technology 128(3):129–136 (2004)Google Scholar
- Zou Q, Sun T S, Nassar S A, Barber G C, Gumul A K. Effect of lubrication on friction and torque-tension relationship in threaded fasteners. In STLE/ASME International Joint Tribology Conference San Antonio, TX, USA, 2006.Google Scholar
- Shan L, Wang Y X, Li J L, Li H. Wu X D, Chen J M. Tribological behaviours of PVD TiN and TiCN coatings in artificial seawater. Surface & Coatings Technology 226: 40–50 (2013)Google Scholar
- Cheng D X. Handbook of Mechanical Design. (in Chinese). Beijing: Chemical Industry Press, 2016.Google Scholar
- Yu Z T, Liu J H, Zhang C Q, Zhou J B, Peng J F, Ma L J, Zhu M H. An experimental study on self-Loosening of bolted joints under axial vibration. (in Chinese). Tribology 35(6): 732–736 (2015)Google Scholar
- Yamamoto A. Theory and Calculation of Thread Connection. (in Chinese). Translated by Guo K Q, Gao S J, Wang X F, Xu A L. Shanghai: shanghai scientific and technological literature press, 1982.Google Scholar
- Zhou Z R, Zhu M H. Dual-fretting Wear. (in Chinese). Shanghai: Shanghai Jiaotong University Press, 2004.Google Scholar
- Liu J H. Research on the self-loosening mechanism of bolted joints under axial excitation. Ph. D Thesis. Sichuan (China): Southwest Jiaotong University, 2016.Google Scholar
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