有缝重力坝静动力有限元仿真分析

【作者】 游碧波；

【导师】 乐金朝； 王复明；

【作者基本信息】 郑州大学 ， 岩土工程， 2004， 硕士

【摘要】 重力坝是水利工程中非常重要的筑坝型式，由于其安全可靠，施工技术简单，对地质要求不高等显著优点，在国内外被广泛采用。重力坝的应力和稳定性分析是进行其它设计的基础，是整个设计的重要组成部分。传统的计算方法适应性差，已不能满足设计需要。随着有限元理论的完善和仿真软件的不断发展，采用有限元软件对重力坝进行仿真模拟具有重要的工程意义和实用价值。 本文综述了重力坝的各种分析方法，简要阐述了重力坝有限元分析方法的基本原理。介绍了ANSYS程序结构及其分析的基本过程，重点讨论了ANSYS的模型建立和网格划分，初步分析了四面体和六面体单元对计算精度的影响，并对六面体网格划分方法进行了深入的研究。 结合实际工程，采用ANSYS软件对有缝重力坝结构进行三维有限元计算，对其结构性能进行分析。在计算过程中，考虑了混凝土分区和计算网格精度的影响，并较为系统地研究了混凝土重力坝在建立模型、有限元网格划分以及有限元计算和分析中的各种问题，采用混合网格划分方式实现了对复杂结构的六面体网格划分。 对ANSYS软件中关于接触问题的计算方法进行了详细研究，并通过数值算例的计算分析，对ANSYS采用接触单元模拟接缝的可行性问题进行了探讨。利用接触单元和单元结点耦合方法对接缝和键槽的作用分别进行了模拟。结合实际工程中的不同工况，对某堰闸坝结构的应力和变位进行计算，分析了坝体的应力和变形的分布规律，并重点研究了坝内孔道、闸墩等部位的应力分布状态和坝体局部应力集中，并对应力集中问题提出了具体的处理方法。研究结果为实际工程的设计提供了重要的技术依据。本文结合现有的美国坝工设计规范，对坝体的抗滑和抗倾覆稳定性问题进行了分析，该分析方法对于同类的大体积混凝土结构的抗滑和抗倾覆稳定性分析具有一定的参考价值。更多还原

【Abstract】 Gravity dam is an important structure form in water works. It is widely used in the whole world because of its many advantages such as safety and stability, easy techniques in construction, lower geological requirement and etc. As the foundation of other analysis in gravity dam’s designment, stress and stability’s analysis is an significant segment. Traditional calculating methods have lower adaptability and can’t meet the demand of designment. With the development of FEM theory and simulating software, FEM software’s simulation to gravity dam has great engineering signality and practical value.After Summing up vary kinds of analyzing methods, the FEM theories to the gravity dam are expatiated briefly. Introduced the makeup and analysis procedure of ANSYS software, and the calculating precision difference between tetrahedron element and hexahedron element are discussed, and thorough research are made to the hexahedron mesh method.FEM software ANSYS is adopted to simulate a gravity dam, which is of a real project item. In the simulating process, the concrete classify and mesh precision are take into account, the research outspread in modeling, meshing and other problems in the FEM calculating and analysis, using mixing-mesh method, complex structure’s hexahedron meshing is accomplished.The calculating methods to the problem of contact in ANSYS program are studied, and the contact suture and key groove are stimulated in ANSYS program and analyzed their feasibility by examples. Contact elements and couple method are both used in simulating contact suture and compared the difference. Combine with engineering project of a weir-gate-dam, the stress and deforming are studied in different working condition under complicated loadings, the stress distribution in the cavities and piers are studied with special care, stress concentration problems are studied and a treatment method are carried out.The researching results provide significant technical warranties for the project designment. Take into account the U.S. dam design regulation, the sliding and overturning stability of the dam are calculated, thus have great referenced value to similar dam works’ stability analysis.更多还原