The dynamic characteristics of multi-ply bellows with finite element analysis and modal test

摘要

Vehicle bellows is widely used in piping systems to absorb the vibration, heat and noise developed in expansion and contraction in the exhaust manifold. However, due to its complex structure, it is difficult to perform the finite element analysis. Therefore, from the theory of plate, equivalent thickness and density were supposed and applied in this paper to perform the finite element analysis. In addition, the experimental modal test was performed at 56 response points using an accelerometer and impact hammer. Modeling used in experiment was expressed by simple cylindrical shell. Nut tooled for smooth excitation was fixed to the top end of bellows. And fix the bottom land of bellows to the surface plate by Mix & Fix and Silicon. In this paper, natural frequency and mode shape were obtained by experiment and then be compared to the finite element analysis results to evaluate the dynamic characteristics of bellows. Through the modal test, it was shown that the results calculated by finite element analysis are comparable to those of measured experiment.