ANSYS软件中修正剑桥模型的二次开发

ANSYS软件具有很强的非线性计算功能和前、后处理能力，是目前世界上最强大的通用分析程序之一。标准ANSYS程序中包含众多的材料本构模型，但尚缺少岩土工程数值计算中常用的修正剑桥模型。为扩展ANSYS在岩土工程领域的计算能力，利用二次开发工具UPFs和数据接口将修正剑桥模型连接到标准ANSYS程序中。二次开发的核心是本构模型子程序UMAT.F的编制。子程序的编写一方面要符合修正剑桥模型的本构关系式和弹塑性有限元计算的特点；另一方面变量名和输入输出格式必须和标准ANSYS程序一致。对二次开发后的ANSYS程序进行了典型算例的验证。结果表明，在ANSYS中加入修正剑桥模型的方法是可行的，可推广到ANSYS对于其他材料本构模型的二次开发中。

Secondary development of modified Cambridge model in ANSYS software

The software ANSYS is one of the most powerful nonlinear finite element analysis programs in the world. It includes different kinds of material models. However, the ANSYS currently lacks modified Cambridge constitutive model which has been widely used to simulate the stress-strain behavior of soil in geotechnical engineering. The secondary development tools UPFs and data interface have been used to add the modified Cambridge model to standard ANSYS procedure. The key technology of secondary development is the compilation of subroutine UMAT. F. The subroutine must in accord with the constitutive equation of the modified Cambridge model and the rule of finite element computation. Its variable names and input-output formats must be consistent with standard ANSYS procedure. A numerical example is given; and the result verifies that the secondary development of the modified Cambridge model is valid. The method mentioned can be extended to add other material constitutive models to standard ANSYS procedure.