The finite element method(FEM) based on the plastic deformation theory is more and more widely applied to the rapid simulation of sheet metal forming. Based on the ideal forming theory, the forward FEM of sheet metal forming is suggested. Focusing on the problem of the kinematic controlling of the mesh nodes of a part on the three dimensional sliding constraint surface, we adopt the strategy of three coordinate systems and two kinds of transformation to construct the governing equations of forward FEM based on the local coordinate system of each node, and then we solve the governing equations of forward FEM with Newton-Raphson iteration. Finally, the home-codes of inverse and forward finite element methods are respectively used to simulate the drawing forming of' an irregular box part. The results, given in Figs. 7, 9 and 10, and their analysis show preliminarily that the forward finite element method can be carried out for the rapid simulation of sheet metal forming by the strategy of the three coordinate systems and two kinds of transformation, and, compared with the inverse FEM, the forward FEM is more efficient for predicting the formability and shape of deformed parts.%基于塑性形变理论的有限元法在板料成形快速模拟中得到了越来越广泛的应用,三维空间构型网格节点的运动控制已经成为了其中一个关键问题.在理想成形理论的基础上,提出了板料成形正向有限元法；针对零件网格节点在三维空间滑移约束面上的运动控制问题,采用三套坐标系与两种坐标转换的策略,基于节点局部坐标系建立正向有限元控制方程,然后进行Newton-Raphson迭代求解；分别运用自主开发的逆向与正向有限元程序,对一个不规则盒形件的拉深成形进行模拟.结果表明,采用三套坐标系与两种坐标转换的策略,实现了正向有限元法在板料成形快速模拟中的应用；相对于逆向有限元法,正向有限元法能够更加有效地预测零件的成形性能与外形.
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