Storage durability life and reliability analysis of welded metal bellows

On the ground of high resistance to pressure, long life and good retractility, the welded metal bellows are widely used by the space industry. Their performance reductions have a serious effect on the system reliability of space products during the storage. The strength and stiffness analysis of welded metal bellows are performed by theoretical research, numerical simulation and test verification in this paper. Moreover, it is ascertained that the main failure mode of bellows is stress looseness. Then the residual load carrying capacity is confirmed as the failure criterion of bellows. The variation of residual load carrying capacity with time is derived on the base of Larson-Miller model. Then, the assessment model of bellows storage durability is based on stress-strength model. At last, some welded metal bellows storage test data are evaluated through this method, and life evaluation on storage durability of bellows is presented. This method is great guidance significance for optimizing the design of welded metal bellows assembly and assessing storage reliability of space products.