Research On Influencing Factors And Their Interaction Regulations Of Dynamic Stiffnes Of Multilayer Bellows

Bellows is the thin-walled cylindrical elastic shell with lateral corrugated and hasthe effect of vibration, noise reduction capacity, sealing, energy storage, thermalcompensation, medium isolation and other functions. Multilayer metal bellows is madeup of multi-layer thin shell structure, compared with the same thickness of single-layerstructure, multilayer bellows has large displacement’s compensation and reducedcapabilities of vibration and noise. It is widely used in piping system. Considering thepractical situation, only when the dynamic characteristics of the bellows in differentwork conditions are investigated, the damage of the bellows which is caused by theresonance can be avoided. Thus, it’s important to discuss the dynamic characteristicsof the bellows.In the present work, numerical simulation and experimental testing, finite elementmodel of multilayer bellows with sandwich damping was built by ANSYS finiteelement analysis software. The influence and interaction regulations of the property ofvescoelasic damping, the geometric parameter and configuration of multilayer bellowson the loss factor of the multilayer bellows, such as the wave height, pitch of wave,diameter, thickness, were discussed and analyzed. The analyzed results showed that：when other parameters were constant, the dynamic stiffness of multilayer bellowswould increase with increasing pitch of wave, diameter, thickness, elastic modulus ofthe damping materials. It would also decrease with increasing the wave height andwave number. However, according to the thickness of the damping materials, when thethickness was less than0.2mm, the dynamic stiffness of multilayer bellows woulddecrease with the thickness increasing. The minimum value of the dynamic stiffnesscan be obtained when the thickness was between0.2mm and0.3mm.When thethickness was more than0.3mm, the dynamic stiffness of multilayer bellows wouldincrease slightly with the thickness increasing.The multilayer bellows was carried on experimental modal analysis. The test result compared with the simulation result, the error was very small. It verified that thesimulation results were accuracy and provided definite reference price of themultilayer bellows with sandwich damping’s design, manufacture and applications.