Influence of viscous medium temperature distribution on sheet fracture in viscous pressure forming at warm temperature
(1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. Shenyang Aircraft Industry Group Co Ltd, Shenyang 110034, China)
2. Shenyang Aircraft Industry Group Co Ltd, Shenyang 110034, China)
Abstract: Viscous pressure forming (VPF) of aluminum alloy AA3003 sheet metal at warm temperature was investigated by using coupled thermo-elastoplastic-viscoplastic finite element method. The influence of viscous medium temperature distribution on sheet fracture location was studied and the distributions of fracture factor at different temperatures were obtained by using ductile fracture criterion. The results show that the failure of sheet metal varies with increasing initial temperature of viscous medium. When the initial temperature of viscous medium is near that of sheet metal, the failure location occurs at dome center, and when the initial temperature of viscous medium is too low, however, the failure location occurs at die corner. The occurrence of fracture can be postponed and even prevented through controlling the temperature distribution in viscous medium.
Key words: temperature distribution; aluminum alloy; warm viscous pressure forming; fracture; Tinite element method; numerical simulation