Simulation and experimental study on dynamic response characteristics of vertical pipeline assembly

The preload of bolt connection affects the dynamic response of vertical pipeline structures, which has an important influence on the vibration and noise of hydraulic systems. Based on ANSYS, the finite element analysis model of the prestressed modal of the vertical pipeline connection unit was established. The clamp model was simplified by the equivalent stiffness test and fitting method. Under different preload torque conditions, the natural frequency and mode shape of the pipeline were solved. The modal test platform was established based on the hammering method to verify the error of modal calculation. The harmonic response analysis of the vertical pipeline was carried out, and the accuracy of the simulation analysis was verified by the frequency response test of the power flow parameters. The research results show that the preload load of the bolt has a limited influence on the modal characteristics of the connected pipeline. When the preload torque is about 8 N·m, the structural stiffness tends to be balanced, and under external excitation conditions, no large resonance amplitude will occur.