【摘要】 基于连续介质力学及有限变形理论，建立了退化四节点壳单元的动力有限元模型，用于覆盖件成形分析．数学模型采用物质坐标系中的修正的拉格朗日描述，采取集中质量矩阵，用动力显式积分的方法，使位移计算显式化，避免了由材料、几何、边界条件等高度非线性因素引起的计算收敛问题．根据此模型编制的程序模拟了一方形覆盖件的成形过程．更多还原

【Abstract】 Based on the continuum mechanics and the finite deformation theory, a finite element model for simulating the panel forming process has been developed with the degenerated four-node shell element. In the model, updated Lagrangian formulation in the current coordinate system has been adopted. In integration, explicit formulation has been used with the lumped mass matrix so that it facilitates the calculation of the displacement and ayoids the convergence problem caused by the nonlinearities in material, geometry, and boundary conditions. A program based on the model to be used in the simulation of the forming process of a square panel has been written.更多还原