Keramat Malekzadeh Fard - Department of Structural Analysis and Simulation, Space Research Institute, MalekAshtar University of Technology, Tehran-Karaj Highway, IRAN, Post Box: 13445-768, Tehran, IRAN
Gholamhasan Payganeh - Faculty of Mechanical Engineering, ShahidRajaee Teacher Training University (SRTTU), Tehran, IRAN,Post Box: 16785-163,
Javad Shahbazi Karami - Faculty of Mechanical Engineering, ShahidRajaee Teacher Training University (SRTTU), Tehran, IRAN,Post Box: 16785-163,
Orang Chaeichi - Faculty of Mechanical Engineering, ShahidRajaee Teacher Training University (SRTTU), Tehran, IRAN,Post Box: 16785-163,

Aluminum alloys, due to their light weight and resistant against corrosion, play a significant role in aviation and automotive industry. Hydroforming process can be used for the formation process of Aluminum alloys.In some applications such as applications in transferring very high temperature corrosive fluids in which , use of Bi-layered pipes are recommended.This paper is divided to two parts: in the first part, formation process of a two layered isotropic Aluminum-Copper pipe is simulated using a 3D finite element method. In the second part, to validate the simulation results, an experimental machine of hydroforming pipe with the capability of controlling the internal pressure and axial feeding is designed and built. Linear loading curve was selected as the best loading curve for the formation process based on a comparison between three different type of loading curves (linear, step-wise, and spline). Also, comparison between thickness distribution of hydroforming of single layer and two layered pipes showed that two-layered pipe has more homogenous distribution.According to the results, wrinkles created before bulging the pipe plays the role of axial feeding very well and the pipes have better thickness distribution.Experimental results verified simulation outcome can be used to predict loading curves with a reasonable tolerance.

Tube hydroforming, two-layer connections, loading curve, thickness distribution, Finite element simulation