Study On Axial And Bending Properties Of Weld Bellows

Edge welded metal bellows is a kind of new components, which used in various sectors of the national economy widely. With conventional hydroforming, roll forming, mechanical forming and depositing bulging, it has the manufacture of high precision, displacement volume, the volume of large compensation and other advantages. At present, China has not yet developed welded metal bellows corresponding national standards. Structural design of welded bellows only reference standard of metal bellows expansion joints. Meanwhile, for the study of bearing movement mechanism, elastic properties, application fields, complex waveforms of the axial stiffness and other issues less.In this paper, edge welded metal bellows were taken as the research object. Its two typical waveform profile - stacked and symmetric, had been studied on by theoretical research and finite element analysis. The main results are as follows:1) Axial stiffness of welded metal bellows was derived by mechanics at linear elastic stage. A comprehensive comparison was made on the theoretical derivation, finite element method, empirical formula. Empirical formula can only be used to estimate, because it does not consider the wave. Results of theoretical analysis and finite element solution agree well with each other, confirm the feasibility of the method.2)The variation of elastic properties of welded bellows under cyclic tension and compression shaping effect was simulated. Meanwhile, the effect of material parameters on the elastic properties was also studied. In the end, we choose the maximum axial stiffness and axial compression ratio to characterize the elastic properties. Considering nonlinear conditions, the influence of structural parameters on the elastic properties was given. Finally, we come to the stack waveform is more suitable for use in an axial load conditions3) Analyzed under pure bending load and combined load:The distribution of equivalent stress and the location of the point of easy damage in the welded bellows; Influence of structural parameters on the bending stiffness and the maximum bending angle of welded bellows is obtained. The results show that the symmetrical welded bellows is more suitable than stacked under bent condition; Influence of structural parameters on the elastic properties was given under combined load.