25.3.4-vumat用户子程序翻译（abaqus帮助手册）.doc

25.3.4?VUMAT 25.3.4?VUMATUser subroutine to define material behavior. 定义材料本构用户子程序 Product: ABAQUS/Explicit?? Warning:? The use of this user subroutine generally requires considerable expertise. You are cautioned that the implementation of any realistic constitutive model requires extensive development and testing. Initial testing on a single-element model with prescribed traction loading is strongly recommended. 注意：用户子程序的使用通常需要一定的专长。用户需要知道执行任何实际的本构模型需要大量的试验数据。强烈建议用户对用户子程序进行在指定拉力作用下单个单元的验证测试。 The component ordering of the symmetric and nonsymmetric tensors for the three-dimensional case using C3D8R elements is different from the ordering specified in “Three-dimensional solid element library,” Section 14.1.4, and the ordering used in ABAQUS/Standard. C3D8R单元三维轴对称及非轴对称张量成分顺序与“Three-dimensional solid element library,” Section 14.1.4及ABAQUS/Standard中指定的顺序不同。 References “User-defined mechanical material behavior,” Section 12.8.1 *USER MATERIAL Overview User subroutine VUMAT: 用户子程序VUMAT is used to define the mechanical constitutive behavior of a material; 用来定义材料的力学本构关系 will be called for blocks of material calculation points for which the material is defined in a user subroutine (“Material data definition,” Section 9.1.2); 可以被用户子程序定义材料计算点调用 can use and update solution-dependent state variables; 可以使用和更新结果依赖状态变量 can use any field variables that are passed in; 可以使用传入的任何场变量 is described further in “User-defined mechanical material behavior,” Section 12.8.1; and 在“User-defined mechanical material behavior,” Section 12.8.1中详细论述； cannot be used in an adiabatic analysis. 可以被用于绝热分析 Component ordering in tensors 张量组成顺序 The component ordering depends upon whether the tensor is symmetric or nonsymmetric. 张量组成顺序取决于其是否为对称或非对称张量。 Symmetric tensors 对称张量 For symmetric tensors such as the stress and strain tensors, there are ndir+nshr components, and the component order is given as a natural permutation of the indices of the tensor. The direct components are first and then the indirec