Friction-Induced Vibrations during Tightening of Bolted Joints—Analytical and Experimental Results

Abstract

Bolted joints are one of the most used machine elements. Holding together structures of all sizes, the integrity rests on their shoulders. Thus, an accurate and reliable assembly of the joint is crucial. While it is the aim to not experience friction-induced vibrations at all, at some situations, it is unavoidable. These cases, however, have yet been out of the focus of control algorithms due to the volatile nature of the process. This contribution delivers analytical and experimental results for the occurrence of friction-induced vibrations during tightening of bolted joints. Previous findings of system characteristic constants could be validated, which can be used to monitor the tightening process even while strong vibrations during the tightening process occur. Additionally, a real-time algorithm is presented which allows for an advanced process monitoring and control by identifying process characteristics based on which predictions of the process can be made. These measures significantly improve the capabilities to reach the target values of the tightening process.

Energy flow characteristics of friction-induced nonlinear vibrations in a water-lubricated bearing-shaft coupled system

“…Graf and Ostermeyer [7] have shown how the stability of an oscillator sliding on a belt will change, if a dynamic friction law with inner variable is considered instead of a velocity-dependent coefficient of friction, which demonstrates the unstable vibration can even be found in the case of a positive velocity-dependency of friction coefficient. Baramsky et al [8] contributed the analytical and experimental results for the occurrence of friction-induced vibrations during tightening of bolted joints of the most used machine elements. Niknam and Farhang [9] employed a two-degree-of-freedom single mass-on-belt model to study friction-induced instability due to mode-coupling, in which numerical analyses are used to tackle the effect of three parameters related to belt velocity, friction coefficient, and normal load on the mass response.…”

Stochastic Model Updating of Bolt-Jointed Structure for Structural Dynamics Applications

“…Besides, different sources of uncertainty usually arise in the system and contributed to the high variability in the experimental responses, which is the dynamic behaviour of the structures. The major sources of uncertainty that contribute to the variability in the bolt-jointed structure responses are when the bolt joints disassembled and reassembled repeatedly, self-loosening due to vibration and slippage [11], [12].…”