Experimental study of loosening behavior of plain shank bolted joint under dynamic loading

Abstract

Purpose – Bolted joints are commonly used to connect structural members. These joints can be disassembled whenever required. Various types of washers are used between nut and the connected member to keep the joints tight. However, these joints often become loose over time under dynamic loading conditions. The purpose of this paper is to know the reasons of loosening of bolted joints and to identify the main parameters that contribute to the bolt loosening, and to verify them with previous work. Design/methodology/approach – This work studies loosening of bolted joint in a test rig under varying tightening torque as well as for various types of washers used as the number of load cycles increases. Four trial runs are taken for each case considered and the average results are found out to minimize possible sources of errors. For the purpose, a specifically made test rig is used which is capable of applying harmonic load on the bolted joint by the lever action. Findings – The study compares the loosening of bolted joint with and without washer, and also under different initial tightening conditions. This study has shown the suitability of the test rig, methodology and parameters for study of loosening in bolted joints. This study presents an indigenous test, capable of applying harmonic load on bolted joint. Originality/value – The results establish that the methodology and parameters selected were appropriate for the purpose of study of loosening of bolted joints. This study has provided a base line for further work to understand the loosening of bolted joints.

Role of helical spring locked washer in bolted joint analysis: a review

“…Patil et al (2006) did the parametric study on bolted joints for self-loosening performance of it. Saha et al (2007) developed test rig for study of anti-loosening phenomenon of different threaded fasteners. Dalal and Thakur (2013) evaluated effect of transverse vibration on loosening characteristics of multiple jack bolt nut using Junker apparatus compared results with SW performance and also Kumar (2013) in his works, mentioned the causes and remedies of loosening of nut, bolts pretension assembly with different types of washers also use Junker test apparatus.…”

“…Dravid et al (2014) compared loosening performance of different types of washers using his developed test rig under different applied torques. Dravid et al (2015) did his work on experimental study of plain shank bolted joints with plain washer, SW and without washers for loosening evaluation.…”

The influence of thread screw parameters on the efficiency of threaded joints

“…Given the importance of preload [1][2][3], various methods have been devised for its measurement during the tightening process [4][5][6][7]. The tribological conditions of the threaded joint play a major role in achieving the precise preload value [8].…”

Prognostic analysis of fastener joints in straight attachment lugs

“…The work by Kathiresan et al (1986) provided solutions for lug joints with rigid pin and provided solutions which are valuable for the purpose of comparison for the present work. Besides the aforementioned studies, there are recent contributions regarding loosening of bolted joints (Dravid et al , 2015) and corroded welded joints (Gopalkrishnan et al , 2011). These aspects are important but can only be included when considering the bolt clamp-up pressure and corrosion effects.…”