凸曲台件凸模支撑渐进成形路径方案研究

Research on path scheme of convex curved parts with punch support by incremental forming

针对单道次凸模支撑渐进成形大切角凸曲台件时出现的减薄带或破裂现象,提出了4种多道次凸模支撑渐进成形凸曲台件的路径方案:等高相切逼近型、等高平行直线逼近型、等增量切角相切逼近型和等弧长相切逼近型。基于ANSYS/LSDYNA分析平台建立了凸模支撑渐进成形凸曲台件的有限元模型,在不同板料厚度和成形道次数目的情况下,通过数值模拟和物理实验研究了所设计的4种多道次路径方案成形出的凸曲台件曲面部分壁厚减薄率分布情况。结果证明了该4种成形路径方案的合理性和可行性。分析表明,板料厚度越小或成形道次数目越多,4种成形路径方案成形出的凸曲台件曲面部分的壁厚分布均匀性越高,其中等增量切角相切逼近型路径方案成形出的凸曲台件曲面部分的壁厚最为均匀。

Aiming at the phenomenon of the appearance of thinning band or rupture in single pass incremental forming of large-angle convex curved parts with punch support,four path schemes of convex curved part with punch support by multi-pass incremental forming were proposed,namely,contour tangent approximation type,contour parallel line approximation type,equal-increment chamfer tangent approximation type and equal arc length parallel line approximation type.The finite element model of convex curved parts with convex support in incremental forming was established based on the ANSYS/LS-DYNA analysis platform.Under the conditions of different sheet thicknesses and different number of forming passes,the distribution of wall thickness reduction rate of the curved of convex curved parts formed by the four designed multi-pass path schemes was studied by numerical simulation and physical experiment.The results prove the rationality and feasibility of the four forming path schemes.The analysis shows that the smaller the sheet thickness or the more the number of forming passes,the higher the uniformity of the wall thickness distribution of the curved parts formed by the four forming path schemes,and the wall thickness of the curved part formed by the equal-increment chamfer tangent approximation type path scheme is the most uniform.