主催: 一般社団法人 日本機械学会
会議名: 2020年度 年次大会
開催日: 2020/09/13 - 2020/09/16
Sato et al. proposed the theory of self-loosening of bolt/nut assembly under repeated tensile force considering the slippage between mating threads and bearing faces, and the resulting torsional moment on the bolt. According to this theory, torsional moment on bolt increases also in unloading process. However, this behavior could not be reproduced in the experiment. In this research, the simulation for the experiment conducted was performed using a simplified FE model to observe the behavior of the slippage between mating threads and bearing faces under repeated tensile force, in which bolt thread, nut thread and clamped member are assumed to be rigid with spring elements representing the deformation of the bolt shank and the nut. As a result, it was found that there is a possibility to accumulate the torsional moment even during the unloading process. However, it was not confirmed perfectly since the model was very sensitive by the condition of contact. Moreover, the condition for the beginning of slippage in relation to the coefficient of friction should further be considered since the torque is transformed into “force” in the simplified model.