板材两点对称式渐进成形轨迹的数值模拟研究

Numerical Simulation Research on Two-point Symmetric Incremental Forming Trace of Sheet

针对分层渐进成形中金属板材易破裂的问题,在两点对称式渐进成形工艺的基础上,建立了有限元模型,确定了工具头的加工轨迹,选定合理的工艺参数。采用分层渐进成形和螺旋渐进成形的方式,利用MSC.MARC软件对圆锥台制件的渐进成形过程进行了数值模拟,对比分析了两种成形方式下目标制件的壁厚均匀性、等效塑性应变和应力状态。结果表明:与分层渐进成形相比,螺旋渐进成形使目标制件成形区域的壁厚均匀性提高了2.3%;在螺旋渐进成形方式下,等效塑性应变的变化量更小,变形更加均匀,应力三轴度较小,成形质量更高。

Aiming at the easily cracking problem of the metal sheet in layered incremental forming, on the basis of two point symmetric incremental forming processes, the finite element model was established, processing traces of tool head were determined, and reasonable process parameters were elected. The incremental forming process of conical part was numerically simulated by using MSC. MARC software and using the forming methodd of layer manufacturing and spiral manufacturing.The wall thickness uniformity, equivalent plastic strain and stress state of the target part were analyzed contrastively under the two forming modes. The results show that, compared with layered incremental forming, the wall thickness uniformity of target part under spiral manufacturing is improved by 2.3%; the variation of the equivalent plastic strain is smaller, the deformation is more uniform, the stress triaxiality is smaller, and forming quality is higher under the spiral incremental forming mode.