三维梁单元的弹塑性切线刚度矩阵

Elasto Plastic Tangent Stiffness Matrix of Three Dimensional Beam Elements

采用非线性有限元理论 ,在 U .L列式的坐标系下 ,考虑各向同性强化材料 ,基于 Von-Mises屈服准则和 Prandtl-Renss增量理论 ,推导出三维梁单元的弹塑性切线刚度矩阵 .考虑了位移的高阶项影响和材料的非线性影响 ,对空间梁单元的非线性有限元程序的编制有十分重要的意义 .

Based on the nonlinear finite element theory, an elasto plastic tangent stiffness matrix of three dimensional beam elements is derived. During the derivation, with the coordinates of updating Lagrange formulation, the isotropy of the reinforced material has been duly considered, and the von Mises yield criterion as well as the prandtl Renss incremental theory has been used. Besides, the higher order terms of the displacement and the material non linearity are also taken into account. The results are of great significance to the nonlinear finite element programming for 3D beam elements.