Abstract:

In order to produce high-quality parts by the tube hydroforming figuration(THF),the pressure in the tube should precisely fit the axial displacement at the tube end,and expensive hydraulic equipment is a necessary part.To solve this problem ,a simple method,namely displacement-driven THF,is presented for T-shaped tubes according to the results of finite element simulation and experiments.This method is based on the characteristic that
the tube volume continuously decreases in the THF process.The efect of overfall pressure on the forming result,as well as the reason for wrinkling,was then discussed,and the concept of safe forming zone was proposed.Experi-mental results indicate that,as the proposed method is a simple method without special requirements for equipment,the THF equipment and the process are simplified and the production cost is reduced.

Key words: T-shaped tube, axial displacement, hydroforming, overfall pressure, wrinkling, finite element