关键词: 板材成形, 轴对称拉深, 起皱, 临界压边力, 破裂

Abstract:

Plane stress and plane strain assumptions were adopted to make comparisons respectively in the stress distribution of the flange region in the axisymmetric deep drawing. The values of radial stress differ a little, while the values of circumferential stress vary in a large range, which were calculated under these two conditions. It can be shown from the finite element simulation that the analytical results of the plane stress assumption are very close to the simulation results, which means the plane stress assumption is closer to the actual situation than the plane strain assumption. Wrinkle instability conditions in the flange region and rupture instability conditions of cylindrical parts were constructed under the plane strain assumption. And the formula of critical BHF was deduced from the assumption. The project of critical BHF with drawing position for a specific deep drawing problem was obtained. The analysis results are useful for understanding of the characteristics of different deformation regions in deep drawing process. Also，the analyses are helpful to set up more reliable criterions of wrinkling and rupture. Meanwhile, it is more accurate to predict the forming defects and critical BHF.

Key words: sheet forming, axisymmetric deep drawing, wrinkling, critical blank holder force(BHF), rupture