Study Of Equivalent Damping Of The Multilayer Bellows Considering Fluid-solid Interaction

Multilayer bellows has bit shift compensation capacity, vibration and noisereduction capacity. Multilayer bellows will have a perfect damping characteristicwhen appropriate metal and viscoelastic damping materials are adopted to processthe metal multilayer and sandwich damping layer, thus attaining the purpose ofvibration and noise reduction.Under the influence of the fluid, the fluid force is applied to the structure. Thedeformation of structure in turn affect fluid pressure distribution, and in most cases,the deformation of the bellows is geometric nonlinearity, and the fluid equation isalso nonlinear thus led to the strong nonlinearity in the interaction interface of fluidsand elastomers. Therefore, it is a complex fluid-structure coupling problem.Finite element model of multilayer bellows with sandwich damping was builtby ANSYS software in two ways of considering friction between the layers andwithout considering the friction. and the loss factor of bellows is acquired by modestrain energy method in the article. The loss factor drawn from experimental analysisof multilayer bellows is close to the results of finite element modle of withoutconsiding friction between the layers. This paper analysis the influence of thegeometric parameter such as wave height，pitch of wave, diameter, wall thickness onthe loss factor of the multi-layer bellows. The results show that loss factor ofMultilayer bellows increases with increasing of wave height and decreases withincreasing of the pitch of waves. The loss factor of Multilayer bellows increases withincreasing of the diameter, but the change is little almost negligible. At the sametime, it decreases with increasing of wall thickness, but the change is little. Thepaper also analysis the influence of force load and water medium conditions on lossfactor of multilayer bellows. The results show that loss factor increases withincreasing of the force load, but the change is little. The loss factor of Multilayerbellows first increases and then decreases with increasing of fluid pressure, There is a peak. The added mass of water has little effect on the loss factor of the bellows.The loss factor drawn from experimental analysis of multilayer bellows is close tofinite element analysis results, which provids reference for the design andmanufacture of multilayer bellows.