异型薄壁壳体强力旋压三维有限元模型的建立

基于ABAQUS/Explicit平台,在解决建模过程中有关旋轮定位、旋轮运动轨迹确定、连续变壁厚坯料壁厚定义的实现等关键问题的基础上,建立了异型薄壁壳体强力旋压三维弹塑性动态显式有限元模型。基于该模型研究发现:在成形过程中后期,旋轮前方易于出现金属堆积,从而使后方材料拉薄,尤其是靠近工件口部的部位壁厚剧烈减薄。提出了通过控制坯料局部厚度和旋轮与芯模间间隙的方法来改善成形过程中金属堆积和壁厚过度减薄现象。

3D FE Modeling of the Power Spinning of Complicated Thin-walled Shell

Some key technologies during the modeling process have been solved at the first, including the determination of initial position and roller path, and the implementation of the definition of blank thickness which is variable etc, and then based on software ABAQUS/Explicit, a 3D elastic-plastic dynamic explicit FEM model for the power spinning of complicated thin-walled shell has been established. Further, based on this model, metal accumulation has been found occurred easily at the frontage of the roller in the intermediate and final stage of the forming process, meanwhile the metal lies in behind of the roller being pulled to thinner. Especially, the wall thickness near the part opening reduces acutely. Finally, two methods have been proposed to avoid the metal accumulation and the excessive wall thickness reduction appearing in the forming process, by controlling the local thickness of the blank and controlling the clearance between roller and mandrel, respectively.