In this paper, an extended forming limit stress diagram (EFLSD) was applied to predict neck initiation failure in tube hydroforming of metal bellows. The proposed EFLSD was used in conjunction with ABAQUS/ EXPLICIT finite element simulations to predict the onset of necking in tube hydroforming of metal bellows. | Analysis of necking in tube hydroforming by means of extended forming limit stress diagram Engineering Solid Mechanics 2 2014 73-82 Contents lists available at GrowingScience Engineering Solid Mechanics homepage esm Analysis of necking in tube hydroforming by means of extended forming limit stress diagram R. Hashemi School of Mechanical Engineering Iran University of Science and Technology Tehran Iran ART ICLE INFO ABSTRACT Article history In this paper an extended forming limit stress diagram EFLSD was applied to predict neck Received September 20 2013 initiation failure in tube hydroforming of metal bellows. The proposed EFLSD was used in Received in Revised form conjunction with ABAQUS EXPLICIT finite element simulations to predict the onset of October 14 2013 necking in tube hydroforming of metal bellows. The amount of calibration pressure and axial Accepted 20 February 2014 Available online feeding required to produce an acceptable part in finite element method FEM were compared 21 February 2014 with the published experimental data and a satisfactory agreement between the FEM and Keywords published test results was achieved. Therefore the present approach can be used as a reliable Hydroforming criterion for designing metal bellows hydroforming processes and reducing the number of Simulation costly trials. Bursting 2014 Growing Science Ltd. All rights reserved. 1. Introduction Hydroforming is a fundamental forming process. This technique was developed at least six decades ago Assempour et al. 2010 . In recent years there has been an accelerating growth in the production of hydro-formed products. Regarding process features and various blanks hydroforming can be classified into sheet hydroforming and tube hydroforming Lang et al. 2004 Hartl 2005 . In tube hydroforming a relatively thin-walled tube is inflated by internal pressure and is forced to conform to the shape of the die which surrounds it Korkolis and Kyriakides 2008 . In the .
