Experimental and finite element investigation of formability and failures in bi-layered tube hydroforming

Optimization of the operating conditions is one of the most significant studies in the hydroforming process, which affect the forming of successful components. In this work, a finite element model was established for bi-layered tube hydroforming process using ANSYS LS-DYNA pre-processor and LS-DYNA solver in order to predict the most efficient and acceptable operating condition for certain material properties and initial blank geometry. Experiments were conducted to check the model validation and the resultant bulge height and thickness reduction were seen in good agreement with the numerical results. The major failure modes of the process were investigated. Different sets of loading paths (relations between axial feed and internal pressure) were tested and compared to each others. Applying internal pressure in advance of the axial pushing was found to give the best formability for the process. (C) 2011 Elsevier Ltd. All rights reserved.