Numerical modelling of the self-loosening of a bolted assembly
Résumé
Self-loosening is a phenomena which is happening when a bolted assembly is transversally solicited. It is characterized by a loss of preload induced by the screw or nut rotation [1]. One of the research preoccupations of the aeronautical and spatial field is to prevent the likelihood of the screw loosening in order to ensure the integrity of the assembly function. Some numerical models were done in the past [2] [3] [4]. However, only a few among them were considering nut and screw threads. Moreover, most of them were validated thanks to the Junker test bench. The latter factors the sliding between the threads of the nut and the screw in the self-loosening. It enables to characterize the effectiveness of a locking solution but does not match with industrial needs as the created assembly get off the industrial one. Consequently, a double lap test sample will be numerically and experimentally studied. In this paper, a numerical model of a double shear test sample will be constructed. The latter will be using aeronautical titanium screws and steel nuts. As soon as the phenomenon is numerically reproduced, some experimental results would be used in order to confirm the built model. Once the model is validated and based on the Kasei theory [5] [6], an explanation of the self-loosening process will be proposed.