Loosening mechanism and influencing factors of fastening connections based on lateral vibration conditions

A finite element simulation model of a fastening connection structure under lateral vibration conditions was established using the finite element analysis method, and the effects of initial preload force, load amplitude, load frequency, and friction factor on the anti-loosening performance of bolts were studied. The results show that an increase in initial preload force could significantly increase the frictional force on the contact surface, thereby enhancing the antiloosening performance of bolt connections. However, excessive preload force could cause plastic deformation of bolts, thereby weakening the overall reliability of the connection. The larger the load amplitude, the faster the loosening process of the bolt connection, and the reliability of the connection also decreased accordingly. With the increase of load frequency, the loosening rate of bolt connection significantly accelerated. With the increase of friction factor, the antiloosening performance of threads was significantly enhanced.