【作者】 王海娟；

【导师】 辛全才；

【作者基本信息】 西北农林科技大学 ， 水利水电工程， 2010， 硕士

【摘要】 拱坝是固结与基岩上的高次超静定的整体性空间壳体结构,其几何形状、边界条件和应力状态都比较复杂。对于目前应用广泛的有限元求解应力的方法,计算出来的结果由于应力集中而导致坝体与基岩交接处数值相对偏大,与实际情况不符。故一些学者提出了有限元等效应力法,然而应用以往的有限元软件进行拱坝等效应力计算是件繁琐的工作,往往需要将结果数据通过人工采集后另外编程计算,不利于工程界大规模的推广应用。因此,研究一种新的等效应力求解方法显得很有必要,ANSYS软件是一个多用途的有限元分析软件,本文利用其APDL参数化设计语言对拱坝有限元等效应力进行了二次开发,使等效应力的计算变得简单方便,易于掌握,为有限元技术在拱坝分析中的广泛应用提供了有力的支持。自重是拱坝的主要荷载之一,对坝体的应力有着很大的影响。在计算拱坝应力时,大多数情况都假定拱坝在建完以后,结构自重按照一次性施加上去进行计算的。然而,拱坝在施工过程中是分缝、分层、分块进行浇注,并且随着施工的具体进程进行接缝、灌浆、封拱等施工程序,逐步形成整体受力结构。有的大坝尚未全部建成就开始蓄水。因此考虑实际施工过程对拱坝应力进行研究也是一项有意义的工作。故本文考虑不同自重施加方式对坝体应力的影响做了深入的研究。本文的研究内容和结论如下:(1)论述了拱坝的发展概况,应力分析方法及有限元分析方法的现状。对有限单元法的基本原理进行系统的介绍,阐述拱坝有限元仿真分析中的常用单元及其适用条件。(2)基于ANSYS软件建立了拱坝三维有限元实体模型,对坝体在不同工况下的受力与变形特性进行计算分析,利用ANSYS软件的APDL参数化设计语言对拱坝有限元等效应力进行了二次开发,并对坝体与坝基接触面的应力集中区域进行等效应力计算。得知通过有限元等效应力的计算消除了应力集中的影响。(3)依据工程实例初步探讨了考虑拱坝实际施工加载过程坝体的应力,并对计算结果进行了对比分析。更多还原

【Abstract】 Arch dam is three dimensional elasticity hyperstatic integrity elasticity shell structure, solidified to bedrock. The scale shape,boundary condition and stress analysis of arch dam is very complex. The results of interface between dam and bedrock is relative larger because of stress concentration, which is calculated by finite element method and is unconformity to practical considerations. Therefore, some scholars have proposed the finite element equivalent stress. However, It is a tedious work to calculate stress concentration by applicating the previous finite element software, which need to collect the results of data by manually then to program calculation. The method is unhelpful to applicate on large-scale popularization of engineering. Therefore, It is necessary to research a new method. ANSYS software is a multi-purpose finite element analysis software, In this paper, make the second development to the arch dam equivalent stress by using APDL parametric design language, which make the calculation of equivalent stress become simple and ease to master. The new method provides a wide application of strong support for the finite element analysis of arch.Weight is one of the most important dam Load and has great impact on the dam stress. When calculate the dam stress, In most case assume that structural weight is put up one-time to calculate the stress after completion of arch dam. Therefore, Arch dam are often poured by parting, layering, sub-blocking during construction, and conduct joint, filling, sealing and other arch construction procedure with the specific process of construction. Then form overall force structure gradually. Some of the dam began to store water when have not yet fully completed. So it is also a meaningful work to study the stress on the arch dam with considering the actual construction process. So in this paper the author make deeply study on stress of dam with considering different ways to impose weight. The contents and conclusions of this study are as follows:(1) This paper discussed the development of arch dam condition, the method of stress analysis and the status of finite element analysis .(2)Established the three-dimensional finite element model of arch dam by using ANSYS finite element software. Calculated and analyzed the stress and deformation properties of arch dam under different cases. Calculated the stress concentration region of dam and dam foundation interface by using equivalent stress method to solve the correspondinglinear stress.(3) Calculate and analysis the dam stress at imposing weight by different ways with considering the actual construction of arch dam and make a comparative analysis based on the actual project.更多还原