基于ABAQUS建立土体本构模型库的研究

Development of static constitutive model library for soils based on ABAQUS

ABAQUS作为一种强大的通用有限元分析程序,具有很强的非线性计算功能和前、后处理能力。但标准ABAQUS程序中的土体本构模型,没能反映土体的剪胀、软化与硬化、应力路径对变形的影响等,因此,有必要在ABAQUS中开发出更适合于土体特性的本构模型库。为拓展ABAQUS在岩土工程领域的计算能力,利用二次开发工具UMAT数据接口,开发出更适合于工程应用的土体本构模型库,如邓肯模型、南水模型及状态相关的砂土模型,不仅可以充分利用ABAQUS程序方便、快捷的前后处理和强大的非线性求解平台,而且还可以完成更有针对性、更切合实际土体应力-应变有限元的数值计算,为工程实践提供技术支持。从计算过程、模拟结果与试验结果比较来看,二次开发模型库子程序运行稳定,模拟结果正确、可靠。

As a powerful universal finite element analysis program,ABAQUS possesses immense ability for nonlinear computing,pre-and-post-processing.But the constitutive model of soil adopted in standard ABAQUS is inadequate in terms of the inability of reflecting militancy of cohesive soil,strain-softening and hardening of sand as well as the impact of stress path on deformation,etc.So it became an emergency for new constitutive model library which is more suitable for soil to be added into ABAQUS.In order to enlarge the computing ability of ABAQUS in the area of geotechnical engineering,new constitutive model library such as Duncan-Chang model,NHRI model and Sand model which are more adaptive for engineering application were developed with the help of secondary development toolkit UMAT as well as data interface.In this way,the convenient pre-and-post-processing and powerful nonlinear solving platform were made full use of in the study,and that more pertinent and more realistic finite element calculation for the stress and strain in soil can be accomplished,which is able to provide technique support for engineering practice.A numerical example is given;and the results verity that the second development of constitutive model library is valid.