The Process Study On Creep Forming For7475Aluminum Alloy Integral Stiffened Ribs Panel

Abstract:Stiffened integral panel, with complex shape and structure, has the prominent structural ratio. Creep forming is a method which uses the creep features of metal to combine the artificial aging and creep forming. There is few research in domestic, so no off-the-shelf technology can be refered to. This thesis will use creep forming to form the stiffened integral panel, which selects a7475aluminum alloy aircraft plate designed by Shanghai Aircraft Design and Research Institute. The creep forming finite element simulation and test of the components and the full-size integral panel will be carried out. This thesis also study the forming process and forming parameters, which basically meet the technological requirements of the designer and bring some useful references to the large aircraft manufacturing programs in China. The main research work and conclusions in this process include:(1) The related geometry parameters of typical components were obtained by using CATIA. A set of four point bending mould carry out the study on creep forming process, and the key parameters of the best properties were170℃/16h.(2) Numeric iteration compensation model was used to virtual the springback into the stiffened panel forming process, which was simulated by using the Abaqus software. The different mechanical status between the ribs and plate were also simulated,which found that the ribs structure is important to the forming of integral panels.(3) Reserch the key process parameters of rib panel forming and defects treatment method, optimize the structural design of the wall structure.(4) Test of typical creep forming panel of a full size with the proportion of1:1, the appearance and performance test of formed panels were carried out, which meet the design requirements and achieve the goals of studying.