Torsional Load Influence on the Bolt Joint Self-Loosening at the Resonant Frequency

Loosening of an assembly is a critical phenomenon, it can cause damage in the aeronautical field which uses a huge number of bolted joints. It should be studied correctly to avoid catastrophic phenomena. Most of studies focused on the loosening phenomenon resulting from transversal load or axial load. This paper is dedicated to the study of the influence of vibration in the torsional direction on the loosening phenomenon. A finite element model is performed on an assembly subjected to vibration resulting from a shaker and exited at its second Eigen frequency. Two configurations will be studied to show the influence of the shaker position on the loosening phenomenon. A bracket is fixed on the shaker to transmit vibration to the assembly. The influence of the bracket length on the loosening phenomenon will be tested. A simplified model of the bolted joint is adopted for the simulation of the loosening to minimize and simplify the numerical problem.