中厚板的反挤凸柱成形规律

运用有限元软件DEFORM-3D对5 mm厚的20钢中厚板进行了反挤凸柱成形模拟研究,对比分析了封闭式模腔、全开式模腔、半开式模腔挤压成形时材料的变形特点。研究揭示了3种成形方式下金属的流动规律、等效应力及等效应变的分布、载荷与行程的关系,从而可根据成形载荷、凸柱高度与凸凹模行程的关系来合理选择模腔形式。进而研究了凸凹模圆角半径、凸柱直径与坯料初始直径之比d/D、凸凹模下行速度等因素对于各挤压方式下凸柱高度的影响。最后,选取半开式模腔成形凸柱进行实验,实验结果和有限元模拟结果符合较好,验证了有限元模拟的准确性。

Forming laws of lug boss backward extrusion for medium-size plate

Forming simulation on lug boss backward extrusion for steel 20 medium-size plate with 5 mm thickness was implemented by finite element software DEFORM-3D, and material deformation features in close die cavity, open die cavity and jar die cavity were compared and analyzed.The study shows that the sheet metal flowing laws, equivalent stress and equivalent strain distribution, relationship between load and stroke under three die cavities are explored, and die cavity type can be appropriately selected according to the relationship between load, lug boss height and punch-die stroke.Furthermore, influences of punch-die corner radius, d/D (d=lug boss diameter, D=initial diameter of part), punch-die velocity on lug boss height are researched for different extrusion modes.At last, the lug boss with half open die cavity is formed, and experiment results agree well with simulation results, which shows accuracy of finite element simulation.