【作者】 孔戈；

【导师】 金星；

【作者基本信息】 中国地震局工程力学研究所 ， 防灾减灾工程及防护工程， 2004， 硕士

【摘要】 随着震害资料的积累和对地下结构抗震性能研究的深入，人们逐渐认识到了用拟静力方法进行地下结构地震反应分析具有的较大局限性，而动力有限元方法更为可取。本文的工作就是围绕地下结构地震反应的动力有限元仿真分析这一问题展开的，具体工作如下。 1．对地下结构地震反应分析方法以及水平成层场地地震反应的分析方法也进行了概括总结，提出了所存在的问题和本文的重点研究工作。 2．提出了一种基于外挂程序包的ANSYS二次开发方法，实现了国际上最为流行的大型通用有限元软件ANSYS和中国地震局工程力学研究所开发的二维显式有限元波动程序包LAND的结合，一方面大大增强了LAND程序前后处理的能力，另一方面也提高了ANSYS分析动力问题时的计算效率和精度。 3．提出了一种直接基于ANSYS求解器的开发方法，这种方法利用APDL语言和(?)IDL语言编程，通过内部数组与ANSYS求解器交换数据，使ANSYS在进行土—地下结构系统动力分析时，每计算一步，都用透射公式对边界节点的位移进行一次修正，从而实现了多次透射边界条件。这种方法在充分利用ANSYS求解器强大功能的基础上，提高了进行地下结构动力反应分析时的计算精度。 4．推导了李小军积分格式的增量形式，并据此离散动力平衡方程。同时，采用Pyke提出的土动力本构模型以及多次透射边界条件，提出了一种场地地震反应一维非线性分析的方法，并据之编制了计算机程序。数值实验表明，这种组合方案能较好的模拟土层在强地震作用下的非线性特性。 最后，对全文的研究工作进行了总结，并讨论了今后进一步的工作。更多还原

【Abstract】 With the accumulation of seismic disaster data and the development of scientific research, people have gradually realized the deficiency of pseudo-static mechanics method when analyzing the seismic response of underground structure. On the other hand, the dynamic finite element method is considered to be preferable. The main research work of this paper focuses on the application of this method to the seismic response analysis and simulation of underground structure, which could be summarized as the following four aspects.1. The research advances of seismic response analysis of underground structure as well as horizontal layered soil site are briefly summarized. Thereafter, the limitation of existing methods and the main studies done in this paper is pointed out.2. Based on redeveloping skills, an approach is put forward to realize the organic combination of ANSYS, a general purpose finite element modeling program, and LAND, a procedure developed by Institute of Engineering Mechanics, China Seismological Bureau, for numerically solving two-dimensional wave motion problems. This approach can greatly enhance the capacity of preprocess and post process of LAND, while improving the computational efficiency and accuracy of ANSYS when dealing with dynamic problems at the same time.3. Via programming in APDL and UIDL language, an additional software package is developed to simulate the multi-transmitting boundary by adjusting the displacement of nodes on the artificial boundary in every iteration when dynamic response of soil-structure system is analyzed with ANSYS. This software package shares data with ANSYS solver through inner arrays. The results of numerical examples manifest that this approach can improve the computational accuracy of ANSYS in dynamic response analysis of underground structure.4. Based on the previous study of Li Xiaojun, a incremental-iterativeIIscheme is presented, which is used to discretize the dynamic equation. Combining the dynamic nonlinear constitutive model of soil presented by Pyke, the multi-transmitting boundary condition presented by Liao Zhenpeng and the numerical integral method mentioned above, a new approach is proposed to predict the nonlinear seismic response of horizontal layered soil site and a computer program is worked out with the help of the same ideas. As is demonstrated by numerical examples, this approach can significantly improve the simulation of the nonlinear characteristics of soil site under strong seismic motions.更多还原