【作者】 张吉；

【导师】 陈岱林；

【作者基本信息】 中国建筑科学研究院 ， 结构工程， 2011， 博士

【摘要】 随着建筑结构的不断发展,结构的计算分析工作越来越复杂,面对计算量巨大、设计效率要求又高的现状,高性能的有限元计算分析软件的研究越来越重要。本文针对建筑结构有限元计算中的几个关键技术问题进行了系统研究,得出一些切实可行的改进方案,部分已经应用于建筑结构分析有限元软件的开发之中。论文的主要研究内容如下：1)研究了有限元计算分析软件的发展历史与进展,概括归纳了当今国内外主流的分析与设计软件的特点、使用领域。在阅读国内外相关文献后,归纳总结了建筑结构有限元分析计算时遇到的一些常见问题,并进行了详细评述。2)研究了网格质量的评价指标。分析与总结了通用有限元软件ANSYS与SAP2000中的单个网格剖分评价指标,在现有单个网格评价指标计算的基础上,提出了一种新的网格评价指标,该指标能综合考虑单元的长细度、平行偏离程度等；不仅能用于单个网格的评价,而且能用于多个网格组成的有限元整体计算模型,数值计算结果表明该评价指标是高效而又可靠的。3)研究了框架梁与剪力墙连接有限元计算的处理方法。在ALLMAN型带转角自由度膜单元的基础上,通过罚函数法,将独立插值的转角位移场与协调位移场变形梯度的反对称部分建立相等关系并引入单元的泛函当中,构造了改进的带有转角自由度的膜单元。分别采用本文改进单元与梁式约束等方法对双肢剪力墙结构进行对比计算,数值结果表明,本文改进单元具有精度高、数据准备简单,罚参数物理意义明确等优点。4)通过ANSYS提供的二次开发UPFs功能,将改进后单元植入标准分析模块,对单元进行分片检验等测试。测试结果表明,单元能通过各种小片检验,无多余零能模式。各种测题中的结果均显示改进后的单元是一种可靠、性能优越的单元。5)研究了建筑结构中偏心构件的连接处理方法。经过数值算例的试算与对比,建议以基于主从约束的“偏心刚域”方式处理,无论构件长短、粗细,均能准确的计算出构件的位移与内力,从而避免了“刚性”杆件法计算结果与杆件“刚性”相关导致计算内力失真的问题。6)研究了有限元误差估计方法。采用二分加密与自适应计算两种方式,将基于能量误差的误差估计方法应用于简支梁、门形结构等的精度评价,都得出当能量误差小于10%时,位移、内力即能趋于稳定,并针对洞角存在应力集中问题,建议将洞口角点处小范围的面积排除分析域后,采用区域自适应方式进行分析,从而将自适应分析方法推广到高层建筑结构分析之中。并指出在计算资源受限的情况下,对连梁进行加密是一种最为行之有效的提高精度方式,其次是最底层柱的根部。综上,本文针对建筑结构有限元计算中的计算效率和计算精度问题进行了研究,提出了可行的改进方法,为推动高效、可靠的建筑结构有限元计算软件发展起到了一定的作用。更多还原

【Abstract】 With the continuous development of structures, structural analysis becomes increasingly complex. Facing the huge amount of computation, high efficiency design requirements, the research of high-performance structure finite element analysis software(SFEAS) is increasingly important.In this paper, several key issues of SFEAS are systematicly studied and some practical improvements are given, parts of them have been applied to the software develop.The major research are as follows:1) Research on the history and progress of finite element analysis software development.The features of today’s domestic and international mainstream analysis and design software are summed up.After reading the relevant literature, the problems encountered with structural finite element analysis are summarized, and the detailed commentary is made.2) Research on the evaluation index of mesh quality.After the analysis and summary of the single evaluation index of the commercial finite element software ANSYS and SAP2000, a new evaluation index, which could be used by both the single grid evaluation and multi-grid finite element model, is recommended, The results show that the evaluation index is efficient and reliable.3) Research on the finite element solution way of wall-beam connection.With the penalty function method, after the constraint relation between the independent rotation field interpolation and the deviatoric strain tensor part of displacement field was established, a high-precision membrane with drilling-dof was constructed.4)Using the user programming featrures(UPFs) interface of ANSYS, the membrane was implanted. The results show that it can pass most of patch test with no extra zero energy mode.A variety of patch tests show it is a reliable, superior element.In addition, it has a simple data preparation and penalty parameter has a reasonable definition.5)Research on the finite element solution way to connect eccentric components.Through numerical experiments, the "eccentric rigid domain", which based on the master-slave constraint,was proposed. Regardless of component length, thickness, it can accurately calculate the displacement and force, which avoids the wrong results by the "rigid" bars method because the internal forces is dependent on the stiffness of the "rigid" bars.6) Research on the finite element error estimation methods.To improve accuracy,with the use of dichotomy and adaptive mesh method, the energy error estimation method is applied to the accuracy of evaluation of the simply supported beams, door-shaped structure calculation. The result shows when the energy error is less than 10%,the displacement and internal force will stabilize. In order to solve the stress concentration,a small regeion near the hole conner is excluded from the adaptive analysis domain,by which can extends the adaptive method to the analysis of high-rise building. When the calculation capabiltiy is limited,in order to get higher acurrancy,a refined mesh is proposed to use in the connect wall-beams.In summary, the paper has studied some key issues of sturcture finite element analysis which focus on the efficiency and accuracy problems. Some suggustions are given, which may promote the efficient and reliable structural finite element analysis software.更多还原