Numerical analysis and design for tubular hydroforming

To Set an optimum deformation path for tubular hydroforming, the hydroformi ng limit of isotropic and anisotropic tubes subjected to internal hydraulic pressure, independent axial load or torque is firstly proposed based on th e Hill's general theory for the uniqueness to the boundary value problem an d compared with those Of the conventional sheet forming. The influences of the deformation path, the material properties and the active length-diamete r ratio on the nucleation and the development of wrinkling during the free tubular hydroforming are also investigated. The above theory is used as a c riterion and implemented with some new functions ill our ITAS3D, an in-hous e finite element code for simulating the sheet forming, to control the mate rials flow and to prevent the final failure modes from occurring. Finally, the tubular hydroforming of an automobile differential gear box is taken as an example to show the efficiency and usefulness of the algorithm. (C) 200 1 Elsevier Science Ltd. All rights reserved.