硬化土模型在OpenSees中的实现

Implementation of hardening soil constitutive model in OpenSees

为了更好地描述不同岩土的力学行为,将硬化土模型集成于OpenSees中,从刚度参数、屈服函数及塑性势函数3个方面概述了硬化土本构模型理论。基于模型理论,根据隐式积分算法推导出硬化土模型的有限元算法格式并给出实现流程,该算法考虑了屈服面交汇处角区域应力更新问题。结合程序流程和OpenSees接口,将模型在软件中进行了实现,并从理论解及试验对比验证了模型开发的正确性。结果表明:算法推导及程序实现正确。硬化土模型在OpenSees中的实现,弥补了OpenSees三维岩土材料的不足,扩大了OpenSees的应用范围。

In order to better describe the mechanical behavior of different rock and soil,the hardening soil model was integrated into OpenSees,and the theory of hardening soil constitutive model was summarized from three aspects including stiffness parameter,yield function and plastic potential function.According to the implicit integration algorithm,the finite element algorithm format was deduced and the program flow chart was given.The algorithm considered the problem of stress update in the corner region at the intersection of cone-and cap-type yield surface.Combined with the program flow chart and the interface of OpenSees,the model was implemented in the software,and the correctness of the model was verified by theoretical solution and experimental comparison.The results show that the algorithm and program implementation are correct.The implementation of the hardening soil constitutive model makes up for the shortage of 3D geo-materials in OpenSees and expands the application scope of OpenSees.