Numerical simulation and experimental investigation of multistage incremental sheet forming
Numerical simulation and experimental investigation of multistage incremental sheet forming
复制标题
DOI：
10.1007/s00170-013-4870-8
复制
发表时间：
2013-10-01
影响因子：
3.4
通讯作者：
Shen, Junjian
中科院分区：
文献类型：
--
作者：
Li, Junchao;Geng, Pei;Shen, Junjian
板料渐进成形（ISF）过程中，通常采用多道次成形的方法来成形那些具有陡峭角度甚至垂直壁面的零件。为了进一步研究多阶段渐进成形，基于实验验证的有限元模型，采用不同的成形策略成形30 A °壁面角的圆锥台，研究了成形阶段数n和相邻两阶段间的增量壁面角α对ISF成形性的影响。对模拟结果进行了详细分析，包括板厚分布、等效塑性应变、回弹量等。结果表明，随着n的增大，最小厚度增大，厚度分布更加均匀，但由于各成形阶段回弹量的积累，回弹量相对于单道次工艺增大。并给出了计算n值的表达式。此外，最大厚度减少最初减小，然后随着匕首alpha值的增加而增加。同时也表明，回弹量与刃形α值无关。
Multistage forming is usually adopted to form those parts which have steep angles or even vertical walls during incremental sheet forming (ISF) process. In order to study the multistage incremental forming further, based on a finite element method model which was experimentally verified, different forming strategies were adopted to form a frustum of cone with a wall angle of 30A degrees to research the influence of the number of forming stages (n) and the incremental wall angle between the two adjacent stages (a dagger alpha) on the formability of ISF. The simulation results including the thickness distribution, the equivalent plastic strain, and the magnitude of springback were analyzed in detail. It was found that with the growth of n, the minimum thickness increases largely, and more uniform thickness distribution is achieved, but the quantity of springback becomes larger in contrast with a single-pass process because of the accumulation of springback during each forming stage. Furthermore, an expression to figure out the appropriate value of n was given. In addition, the maximum thickness reduction decreases initially and then increases as the value of a dagger alpha grows. Meanwhile, it indicates that there is no relation between a dagger alpha and the quantity of springback.