关键词: 起皱失稳, 实体单元建模, 扇形件充液压缩, 厚向应力, 临界起皱判定线

Abstract: Wrinkling instability was one of the main technical challenges affecting the precise plastic forming of thin-walled parts. The stress state in the thick direction had a great influence on the forming limit of the sheet metals during the sheet forming processes. In view of the above problems， the wrinkling instability of sheet metals in plastic forming processes was studied under different thickness stress conditions. The Buckle-Dynamic algorithm in ABAQUS software was combined with solid element modeling to establish a numerical analysis model of liquid-filled compression of fan-shaped parts， and the accuracy of the simulation algorithm was verified by tests. According to the wrinkling bifurcation theory and numerical analysis results， a method was adopted for defining the critical wrinkling time of the plates considering the thickness stress， and the critical wrinkling limit curve was established under the compression conditions of the plates. The influences of thickness stress on the compression wrinkling behaviors， wrinkle resistances and the positions of critical wrinkling limit curve in space of fan-shaped parts were discussed. The results show that the applications of thick stress may improve the wrinkle resistances of the sheets and improve the forming quality， which provides useful reference and experimental basis for the selection of sheet metal forming parameters and the trial production of typical parts. 

Key words:  , wrinkling instability, solid element modeling, liquid-filled compression of fan-shaped part, thickness stress, critical wrinkling limit curve