Experimental and Numerical Study of the Self-loosening of a Bolted Assembly

The self-loosening of bolted assembly is a phenomenon that has been studied several times in the past. Among the existing solicitations, it has been showed that transverse loading might cause the most severe loosening. Thus, different explanations have been proposed. In spite of their similarity, as they all consider sliding as the root cause, the sliding surface distinguish them one from another. This paper will aim at giving another point of view of the problematic in order to advantage a Zadoks’ theory, which highlights the transverse sliding of components. To do so, firstly a double-shear assembly will be modeled. Its specificities are the preload application by screwing the nut, and the use of a self-locking nut. Secondly, some tests will be done in order to valid the built model. Those experiments will also factor the thickness of the assembly in the self-loosening. Thirdly, the analysis of the numerical results and of the experiments, especially the interface surfaces will give us a clue in order to validate the sliding phenomena, which is according to Zadoks, the movement implying the self-loosening of the assembly.