Modares Mechanical Engineering

Modares Mechanical Engineering

Investigation of the effective parameters in the bulging process and obtaining Forming limit curve of the stainless steel tube by the GTN criterion

Authors
Maryam Geran Gharakheyli
Hamid Gorji
Mohammad Bakhshi
Mohammad Javad Mirnia
Abstract
Tube hydroforming is a process which is considered to produce integrated and seamless parts in recent years. The numerical prediction of tearing to design the right equipment in this process is important. In this study, the formability of 304 stainless steel tube by free bulge test was experimentally and numerically evaluated to determine the forming limit diagram. The Gurson- Tvergaard- Needleman (GTN) is a micromechanical model to predict ductile fracture of metals. In order to determine the defining parameters of the GTN damage model, the experimental tensile test of the standard sample and the finite element simulation using ABAQUS software was performed. Using this criterion in the ABAQUS software and comparing the force-displacement diagram obtained from the experimental tensile test and the finite element simulation, the parameters of the GTN model was obtained by the inverse method. Then, the geometrical parameters of the die in the free bulge hydroforming process were investigated by the GTN ductile fracture criterion and the forming limit diagram of the 304 stainless steel tube was numerically obtained. The experimental tests were also carried out to verify the results of the finite element simulation. It’s shown an acceptable agreement
Keywords
Forming limit curve
GTN ductile fracture criterion
stainless steel tube
free bulge test
Modares Mechanical Engineering
Volume 17, Issue 6
August 2017
Pages 365-376