INVESTIGATION OF LOOSENING RESISTANCE UNDER ASSEMBLY CONDITIONS USING DIFFERENT LOCKING CHEMICALS AND LOCK NUTS

Year 2024, Volume: 7 Issue: 1, 26 - 31, 30.06.2024

Baybars Sarıca Tolga Aydın Samed Enser Umut İnce

Abstract

Abstract

Fasteners are subjected to repetitive and variable loads in the areas where they are used. This situation creates some risks such as loosening or fracture of fasteners, result the failure of the joint. Locking chemicals applied on the bolt to prevent loosening that may occur under assembly conditions are used extensively, especially in the automotive industry. By using locking chemicals selected in accordance with the assembly area and fastener, it is aimed to prevent the loosening of the assembly parts under vibration. There are commercial products that offer different properties that can be used in the mass production of locking chemicals. Within the scope of the study, the performance of three different commercial locking chemicals against loosening was investigated and used standard M8 bolts and nuts. In addition, the M8 DIN 980 lock nut, which is used in joints that are at risk of loosening in vibrating areas, was also added to the studies. Due to the effect of the coefficient of friction on the clamping load, all fasteners were coated with the same coating to ensure equivalence in installation conditions. The vibration performances of the locking chemicals were investigated with the Junker vibration test. The results were analyzed comparatively and the joint condition with the highest vibration resistance was determined. As a result, it was observed that the use of locking chemicals and lock nuts increased the loosening resistance.

Keywords

Bolt, Lock nut, Locking Chemical, Assembly, Junker vibration test

Ethical Statement

I declare that this study is an original study; that I have acted in accordance with the principles and rules of scientific ethics at all stages of the study, including preparation, data collection, analysis and presentation of information; that I have cited sources for all data and information not obtained within the scope of this study and included these sources in the bibliography; that I have not made any changes in the data used, and that I comply with ethical duties and responsibilities by accepting all the terms and conditions of the Committee on Publication Ethics (COPE). I hereby declare that if at any time a situation contrary to this statement I have made regarding the study is detected, I agree to all moral and legal consequences that may arise.

Supporting Institution

Norm Fasteners

Thanks

The authors would like to thank Norm Holding for the opportunity to conduct and present the study.

References

• Goodier, J., Loosening by Vibration of Threaded Fastenings, Mech. Engg. 1945, 67, 798
• Eccles, W. Tribological aspects of the self-loosening of threaded fasteners. University of Central Lancashire, 2010
• DellaCorte, C., Howard, S. A., Hess, D. P., Preload Loss in a Spacecraft Fastener via Vibration-Induced Unwinding, 2018
• Umut, İ., Güden, M., An experimental and comparative study of the self-loosening of bolted-joints under cyclic transverse loading, Sakarya University Journal of Science 2021, 25 (2):498-512
• Sakai, T., Mechanism for a bolt and nut self loosening under repeated bolt axial tensile load, Journal of Solid Mechanics and Materials Engineering 2011, 5 (11):627-639
• Chen, C., Chang, H., Syu, J., In Study on advanced assembly characteristics of locking with radial anti-loosening precision locked-nut while maintaining the design rigidity under dynamic precision fastening system, Journal of Physics: Conference Series, IOP Publishing: 2022, 012025
• Hao, G., Jianhua, L., Huihua, F., Review on anti-loosening methods for threaded fasteners. Chinese Journal of Aeronautics 2022, 35 (2):47-61
• Wang, B., Noda, N.-A., Liu, X., Sano, Y., Inui, Y., Oda, K., How to improve both anti-loosening performance and fatigue strength of bolt nut connections economically, Engineering failure analysis 2021, 130, 105762
• Ganeshmurthy, S., Housari, B., Nassar, S. A., Investigation of the effect of adhesive coating on the performance of threaded fasteners, SAE Transactions 2007, 707-717
• Çavdar, K., Öngerilmeli Cıvata Bağlarında Çözülme Problemleri. Uludağ Üniversitesi Mühendislik Fakültesi Dergisi 2015, 20 (1):103-118
• Hattori, T., Yamashita, M., Mizuno, H., Naruse, T., In Loosening and sliding behaviour of bolt-nut fastener under transverse loading, EPJ Web of Conferences, EDP Sciences: 2010, 08002
• Haviland, G. S., Machinery adhesives for locking, retaining, and sealing. Routledge: 2019
• Boellhoff Kimyasal Diş Tutma Yöntemleri, https://www.boellhoff.com/tr-tr/urunler-ve-hizmetler/ozel-baglanti-elemanlari/kimyasal-dis-tutma-yontemleri.php (accessed 13.09.2023)
• ISO, ISO 898-7 Mechanical properties of fasteners - Part 7. International Organization for Standardization Geneva, Switzerland: 1992
• ISO, ISO 16047 Fasteners-Torque/Clamp Force Testing. International Organization for Standardization Geneva, Switzerland: 2005
• Junker, G. H., New criteria for self-loosening of fasteners under vibration. Sae Transactions 1969, 314-335