Experimental study and analytical modelling of a bolted joint subjected to harmonic excitation

This paper presents the experimental work on a single Joint rig and the analytical models for representing the experimental results. A bolted joint connecting two beams is shaken at the resonant frequencies and time-domain data are obtained. These experimental tests have illustrated microslip phenomena from measurements taken locally to the joint interface in the time domain. Hysteresis loops of the torque versus the relative angular displacement of the joint have been generated from the time-domain data of the rig subjected to multiple bolt preloads and amplitudes of excitation. Damping behaviour evolving from linear viscous type to nonlinear frictional type is clearly shown in the plots of the hysteresis loops and the frequency spectra of the relative angular displacement of the joint. As microslip in the joint develops, the hysteresis loops deviates from an ellipse and the contribution from superharmonics in the frequency spectra becomes stronger. The Jenkins-element model for the friction torque in the joint has been used to fit the hysteresis loops of the experimental joint.