Effect of preload force on the nonlinear dynamic characteristics of bolted structure

The bolted structure needs to be preloaded to ensure the reliability of the connection when it is assembled, and the magnitude of the preload force has an important effect on the nonlinear dynamic characteristics of the bolted structure. In this paper, the effect of preload force on the nonlinear dynamic response of a typical bolted cantilever beam structure is analyzed using the finite element method. The results show that when the amplitude and frequency of the external excitation are constant, the response amplitude of the fundamental frequency and multi-frequency of the bolted cantilever beam gradually decreases and then stabilizes as the bolt preload increases. Its motion state changes from chaotic to quasi-periodic motion, then from quasi-periodic motion to multiperiodic motion, and finally stabilizes in single-period motion. The results obtained from this study provide a reference for the design of bolted structures and a theoretical basis for nonlinear vibration response control.