Self-loosening effects on vibration characteristics of plates with bolted joints: An experimental and finite element analysis

Abstract

Vibration characteristics of a plate with six-bolt single-lap joint are investigated in both experimental tests and finite element (FE) method. The FE results are obtained using nonlinear steady-state dynamic analysis via ABAQUS software. The interaction surface is simulated by a nonlinear elasto-plastic thin interface layer. Natural frequencies are measured using experimental modal tests for various bolt tightening torques. The FE model is updated using the direct method and the effectiveness parameters are evaluated by experimental data. Finally, the effect of self-loosening of bolted joints on vibration characteristics of the response signal, including natural frequencies, energy parameters, kurtosis, and standard deviation are investigated. The results obtained from the FE model show good agreement with ones from the experimental modal test. Additionally, it can be concluded that for the bolt loosening defects identification, time-domain processes, and energy-based signal parameters, standard deviation, and kurtosis of the vibration signals are more appropriate rather than natural frequencies analysis.