Aluminum2024(ISOAlCu4Mg1).PDFVIP

Influence of the Effect of Strain Rates on Springback in Aluminum 2024 (ISO AlCu4Mg1) Authors: Pravin Kulkarni Cessna Aircraft Company PO.Box 7704 Wichita, Kansas 67277, USA Email: pnkulkarni@ Tel: 1-316-831-4878 Shashikiran Prabhakar Cessna Aircraft Company PO.Box 7704 Wichita, Kansas 67277, USA Email: pshashikiran@ Tel: 1-316-831-3813 Keywords: Springback, Finite Element Modeling, Strain rate, Hydroforming 4th European LS-DYNA Users Conference Metal Forming II E – II - 27 ABSTRACT Forming of aluminum sheets in T-temper is a much sought after industrial process, especially in the aircraft industry. However, the success of this process largely hinges on the ability to predict springback accurately. Aluminum sheets in T-temper exhibit approximately twenty percent variability in material properties and also the amount of springback is very large. This makes tool design for aluminum in T-temper an iterative and difficult to control process. Traditionally aluminum has been formed in the O-temper and then heat-treated to T–temper, as recourse to reduce springback. This research is aimed at developing a predictive finite element technique for springback, using experimental validation. A parametric study was conducted to determine the influence of geometric parameters and tempers on springback. The study characterizes springback of aluminum in different tempers and investigates the effect of forming strain-rates on springback. The study focuses on springback in Aluminum 2024 using hydroforming process. INTRODUCTION A significant portion of the airframe consists of formed sheet metal details. Forming of sheet metal details frequently involves shaping it into complex patterns by bending through a certain angle so that the metal is stressed beyond its yield point. After the pressure has been relieved, the metal has a permanent set which is less than the angle through which it was bent. The difference betwe