铝板/塑料混合成型中铝板大塑性变形区的有限元分析

采用弹塑性大变形更新的Lagrange有限元方法研究了铝板 /塑料混合成型过程中铝板的成形过程和变形特点。结果表明 ,当塑料熔体压力从 30MPa增大到 5 0MPa时 ,铝板凸缘区已基本不再参与变形 ,铝板上两个板厚减薄较严重的大塑性变形区在此阶段形成。模底接触区与自由变形区交界处的大塑性变形区依次处于板料曲面内双向伸长变形和平面应变状态 ;模腔入口圆角区与自由变形区交界处的大塑性变形区由两部分构成 ,其中与模壁接触部分依次处于板料曲面内双向伸长变形、拉伸变形和平面应变状态 ,另一部分依次处于板料曲面内双向伸长变形和平面应变状态。

Finite element analysis of highly strained zones of formed aluminum sheet by hybrid forming of sheet metal and plastic

The forming process and the deformation characteristics of the aluminum sheet during hybrid forming have been analyzed by the updated Lagrangian finite element method. The results show that the flange of the aluminum sheet has almost no any further deformation and that two highly strained zones with severe thickness reduction are developed when the plastic melt pressure increases from 30?MPa to 50?MPa. The zone between the region contacted with bottom of the mould and the free forming region shows stretch forming and then transferred to plane strain state. Another zone between the mould entry region and the free forming region is constituted with two parts. One neighboring to side wall of the mould shows stretch forming, and then transferred to deep drawing and finally to plane strain state, and the other shows stretch forming and then transferred to plane strain state.