【作者】 何小辉；

【导师】 武振宇；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2007， 硕士

【摘要】 直接焊接相贯节点以其明快的线条、优美的外形受到越来越多工程人员的青睐。其部分节点型式(如β<0.8的间隙型节点)以弦杆表面相对凹凸变形为主,体现出较大的节点柔度。本文采用有限元分析方法,以空间三角形桁架为研究对象,分析了方钢管节点刚度对空间桁架静动力性能的影响。本文主要做了以下工作:(1)根据现有规范及研究成果,设计了方管空间三角形桁架,并进行了桁架支座的设计。鉴于空间桁架不同于平面桁架,而目前规范尚无方管空间节点的规定,本文采用平面节点折减方法进行设计,并指出了空间桁架设计应予以注意的两个问题。(2)应用ANSYS软件,采用SHELL43单元建立了整体桁架模型,考虑材料、几何非线性对其进行了静力计算,并对桁架半跨模型的可行性进行了验证。接着分析了桁架的静力性能,包括桁架的内力分布、整体变形、节点变形及塑性发展、桁架内力重分布和极限状态分析五个方面,并在分析过程中与现有桁架分析模型进行了对比。(3)通过一组变化了节点刚度的桁架,分析了节点刚度对桁架静力性能的影响,提出了一种考虑节点轴向刚度的简化分析模型,并对该模型的可行性及准确性进行了验证。同时指出了推广该简化模型的一种思路,并简要地予以了验证。(4)对一空间三角形桁架的动力性能进行了初步探索,分别进行了模态分析和动力时程分析。更多还原

【Abstract】 Directly welded intersecting joints have been enjoyed by more and more engineers for their lively lines and beautiful outline. Some of these joints, e.g. gap joints withβ<0.8, mostly produce sags and crests on the face of the chord, which embodies the flexibility of the joints. The effect of joint stiffness on the static and dynamic behavior of the spatial triangular trusses is analyzed by the finite element analysis method. Here are the main parts of the analytic work:(1) According to existing codes and research findings, spatial triangular SHS truss and the support of the truss are designed. On account of the differences between the spatial and planar trusses and the lack of the specification about the spatial SHS joints in existing codes, a reduction method to planar joints is adopted for spatial joint design and two attentions about the design of the spatial triangular truss are brought forward in this article.(2) The whole truss model is established by the ANSYS software with SHELL43 element and calculated by considering the material and geometrical nonlinear under dead load. And the feasibility of the half-span model of the truss is verified. In succession, the static behavior of the truss is analyzed by the comparison with the existing truss analysis models, including the distribution of the member forces, the whole deformation, the plastoelastic deformation of joints, the redistribution of member forces and the analysis of the limit state.(3) By a group of the trusses having different joint stiffness, the effect of the joint stiffness on truss static behavior is analyzed. A simplified model considering the joint axial rigidity is proposed and its feasibility and accuracy is verified. At the same time, a suggestion that may popularize the simplified model is put forward and briefly verified.(4) The dynamic behavior of a spatial triangular SHS truss is preliminarily explored by the modal analysis and the dynamic time-history analysis.更多还原