Evaluation of effective parameters in metal bellows forming process

Metal bellows have wide applications in aerospace, micro-electromechanical and industrial systems. Forming process of the metal bellows is very sensitive to increasing the ratio of crown to root diameter. In this state, precise control of the parameters is very important in order to form high-quality metal bellows with good thickness distribution and desirable dimensions and resilience. In this paper, a new method has been proposed for manufacturing of the metal bellows and important parameters such as initial length of tube, internal pressure, axial feeding and velocity, mechanical properties and the type of materials were investigated by finite element (FE) analysis (LS-Dyna) and experimental tests. The explicit time integration method is used for modeling the tube-bulging and folding processes. Meanwhile, the implicit time integration method is used for the spring back stage. Finally, the results of finite element method (FEM) and experiments show a very good agreement. The results of the present work could be used as a basis of designing a new type of the metal bellows. (c) 2008 Elsevier B.V. All rights reserved.