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《Planning》2020,(1)
为了对特高压1 000 kV出线构架节点刚度设计,开展了考虑节点半刚性非线性分析及其对构架力学性能的影响研究。建立了节点的数值仿真模型;对构架中的节点进行分类,并通过非线性有限元方法研究了各类节点的破坏机理及其弯矩-转角曲线;将弯矩-转角曲线应用于连接节点,建立半刚性出线构架有限元模型,研究半刚性节点构架的受力性能,并对比了半刚性节点构架和刚性节点构架在设计荷载和极限荷载下的结构响应。研究发现设计荷载下半刚性节点构架的杆件最大轴力比刚性构架大10.9%,刚性节点构架的极限承载力是半刚性节点构架的2.3倍;随着节点刚度的增加,构架极限承载力呈非线性增加。 相似文献
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梁柱连接组合节点传递着梁柱之间的弯矩和剪力,是钢框架中的重要组成部分,也是钢框架设计中的关键部位之一。弯矩-转角关系是梁柱连接组合节点的主要力学性能,它反映着节点的初始刚度、抗弯承载力和转动能力,直接影响着钢框架体系的变形、极限承载力与整体性能。梁柱连接组合节点连接方式多样、构造形式种类繁多、几何参数多变、各组件受力状态与性能复杂等特性决定了弯矩-转角曲线是非线性的。而弯矩-转角曲线的非线性造成其难以拟合和预测。目前,半刚性连接组合节点的试验与理论研究有了较大的进展。本文归纳和总结了国内外梁柱半刚性连接组合节点弯矩-转角关系研究,包括试验研究和理论模型,并指出了今后需要进一步研究的重点与方向。 相似文献
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空间结构中常用的节点多数都是介于刚接和铰接之间的一种半刚性节点。国内对用于空间结构中的半刚性节点以及半刚性节点网壳的研究目前还比较少。基于半刚性节点的试验研究,得到了螺栓球半刚性节点在弯矩荷载和压弯荷载共同作用下的弯矩-转角曲线。利用大型通用有限元分析软件ANSYS建立了用于空间半刚性网壳结构的有限元分析模型。最后,将由试验得到的节点的弯曲刚度带入半刚性凯威特单层网壳的数值模型中,考虑几何参数和节点刚度对半刚性网壳稳定性的影响,展开了大规模的弹塑性全过程分析,通过系统的参数分析,较为全面地掌握了半刚性单层网壳的稳定性能,并进一步总结得出了螺栓球半刚性节点单层球面网壳的稳定承载力公式。 相似文献
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基于适合结构分析的三参数模型,选取8个节点模型,利用大型有限元分析软件ANSYS 10.0对上下翼缘角钢半刚性连接节点进行分析,并与已有的试验数据进行校准,得到连接节点的弯矩-转角曲线。利用数值分析方法拟合连接节点的弯矩-转角曲线,得到每个节点弯矩-转角曲线的形状系数值。研究表明,利用数值拟合方法得到的拟合曲线和试验曲线与有限元曲线吻合较好,拟合得到的形状系数值相差较小。通过对比节点初始刚度、极限弯矩值以及各曲线拟合结果,建议顶底翼缘角钢半刚性节点的形状系数n取值为1.9。 相似文献
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在进行空间桁架建模时,在节点的处理上通常会采用理想化处理,即简化成铰接或者刚接,但这种简化方法与工程实际相比有一定差别,会导致计算结果的误差[1]。因此,本文通过节点的弯矩-转角关系,采用半刚性节点来模拟桁架的连接方式,务求以一种最切合实际的方式模拟桁架模型。现时M-θr关系曲线的数学模型主要有以下几种:1.线性模型;2.多项式模型;3.B样条模型[2]。本文采用的是线性模型,通过输入弯矩-转角的特征常数来模拟节点的转动刚度。务求用SAP2000得出不同节点模拟方式桁架的受力性能差别。 相似文献
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Concepción Díaz 《Journal of Constructional Steel Research》2011,67(5):741-758
Steel portal frames were traditionally designed assuming that beam-to-column joints are ideally pinned or fully rigid. This simplifies the analysis and structural design processes, but at the expense of not obtaining a detailed understanding of the behaviour of the joints, which in reality, have finite stiffness and are therefore semi-rigid. The last century saw the evolution of analysis methods of semi-rigid joints, from the slope-deflection equation and moment distribution methods, to matrix stiffness methods and, at present, to iterative methods coupling the global and joint structural analyses. Studies agree that in frame analysis, joint rotational behaviour should be considered. This is usually done by using the moment-rotation curve. Models such as analytical, empirical, experimental, informational, mechanical and numerical can be used to determine joint mechanical behaviour. The most popular is the mechanical model, with several variances (e.g. Component Method). A summary is given of the advantages and disadvantages and principal characteristics of each model. Joint behaviour must be modelled when analysing semi-rigid frames, which is associated with a mathematical model of the moment-rotation curve. Depending on the type of structural analysis required, any moment-rotation curve representation can be used; these include linear, bilinear, multilinear and nonlinear representations. The most accurate representation uses continuous nonlinear functions, although the multilinear representation is commonly used for mechanical models. This article reviews three areas of steel joint research: (1) analysis methods of semi-rigid joints; (2) prediction methods for the mechanical behaviour of joints; (3) mathematical representations of the moment-rotation curve. 相似文献
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A new classification system for the joints in lattice shells is proposed. The stiffness and moment capacity of the joints together with the overall structural behavior of the lattice shells are considered in order to establish the classification system. According to this new system, joints in lattice shells can be classified into unique categories: rigid, semi-rigid or pinned. The rigid joints have both high bending stiffness and moment capacity; the semi-rigid joints have both moderate bending stiffness and moment capacity, and the pinned joints have either low bending stiffness or low moment capacity. Determination coefficients α and β are defined, based on the stiffness and moment capacity of the joints, and these are used to establish clear boundaries between the different categories. Some numerical examples are included to demonstrate the validity of the classification system. With the help of the classification system, an efficient process for practical engineering design is proposed, which can help designers choose the appropriate analysis method for lattice shells with different joints. 相似文献
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This paper presents an analysis of semi-rigid beam-to-beam end-plate bolted joints that are subjected to bending and tension or a compression axial force. Usually the influence of axial force on joint rotational stiffness is neglected. According to EC3, the axial load, which is less than 10% of plastic resistance of the connected member under axial force, may be disregarded in the calculation of characteristics of a joint. Actually, the level of axial forces in joints of structures can be significant and has a significant influence on characteristics of semi-rigid joints. One of the most popular practical methods permitting the determination of rotational stiffness and moment resistance of a joint is the so-called component method. The extension of the component method for evaluating the influence of bending moment and axial force on the rotational stiffness and moment resistance of a joint are presented in the paper. The numerical results of calculations of characteristics of joints and calculations of steel framework are presented in this paper as well. 相似文献
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轮扣式钢管支模架节点连接性能试验研究 总被引:1,自引:1,他引:0
设计轮扣式钢管支模架节点半刚性水平力加载试验。选用3组试件,通过对试验现象和所得数据的分析及与扣件式钢管脚手架节点刚度的对比分析,得到结论:轮扣式钢管脚手架节点具有典型的半刚性连接特性,轮扣式钢管脚手架节点的半刚性受不同搭设间距的影响较小;当节点弯矩在控制弯矩的20%以下时,节点的初始连接刚度变化波动略大;当超过20%时,节点连接刚度曲线趋于稳定一致;得到的3组试件节点的连接刚度相当于扣件式钢管脚手架在扣件拧紧力矩40 N.m时的连接刚度。轮扣式钢管脚手架连接稳定性好,搭设质量优于传统的扣件式钢管脚手架。 相似文献
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对半刚性框架进行模拟,研究了梁柱节点转动刚度的变化与半刚性框架位移的关系,以及半刚性连接对不同高度框架变化的影响,为钢结构设计规范考虑半刚性连接的要求提供了相关资料。 相似文献
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半刚性组合节点是一种重要的组合节点形式,更符合工程实际要求。文章收集整理了国内外半刚性组合节点的应用及研究资料,简要介绍了组合节点的分类及国内外半刚性组合节点的研究现状,包括半刚性组合节点的抗震性能及研究时的分析模型。同时归纳了各国学者在半刚性组合节点的研究上所取得的成就。 相似文献
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利用有限元分析软件ANSYS对端板型半刚性组合节点进行了弹塑性有限元计算,分析了组合节点中混凝土板中的纵向钢筋总面积及钢筋强度对组合节点初始转动刚度、弹性极限弯矩和转角及塑性极限弯矩和转角的影响,从而为这种节点的设计提供了参考和借鉴。 相似文献