空间网格结构圆钢管大间隙相贯节点试验研究

针对空间网格结构工程中钢管相贯节点间隙可能出现的大间隙超偏差问题,进行试验研究,结果表明:钢管相贯节点大间隙焊缝对试件承载力影响较小,对试件延性影响较大.     

弦杆受压大直径空间相贯节点足尺模型试验与设计研究

针对贵阳奥体中心主体育场罩篷空间钢管桁架屋盖中的上、下弦相贯节点,进行了足尺节点破坏试验。详细介绍了试验方案、过程、现象和结果。根据试件的受力全过程特点,进行了试验数据分析,了解各加载阶段相贯节点的应力分布情况,得出了此工程节点的破坏模式。并运用有限元软件,从应力、应变和位移三方面对钢管相贯节点进行全过程屈曲分析。揭示了相贯节点的受力性能、塑性区的扩展过程和节点区的应力、应变分布状态,进一步确定了空间相贯节点的破坏准则和承载力确定准则。将节点试验结果、有限元计算结果和规范计算结果进行了对比,并对空间相贯节点的空间相关性予以分析和探讨。     

钢管塔法兰套管相贯节点真型试验研究及有限元分析

钢管塔法兰套管相贯节点的提出,有效地改善了现有大跨越钢管塔节点连接形式在强度、刚度与施工强度方面的不足。通过对TG180与TG273两种型号的法兰套管相贯节点进行轴拉与轴压工况试验和有限元模拟分析,所得数值分析结果与试验结果吻合良好。通过对比ABAQUS有限元模拟结果与真型节点试验结果,探讨两型号法兰套管相贯节点的破坏机理与极限承载力。     

承受弯矩大直径空间相贯节点足尺模型试验与设计研究

结合贵阳奥体中心主体育场钢结构工程,对承受弯矩的大直径钢管相贯节点进行了足尺模型极限承载力破坏试验。对节点试验过程和破坏现象进行了深入研究,分析了各加载阶段相贯节点的应力分布情况及整个加载过程塑性区的发展过程,结合有限元分析对空间相贯节点破坏机理进行分析研究,得出了此类节点的破坏模式,并对该类型钢管相贯节点破坏判定准则进行探讨。通过模型试验来研究承受弯矩大直径相贯节点的设计承载力,并分别与规范计算结果和有限元计算结果进行对比分析,提出设计建议,为有关规范的修改及工程设计提供参考。应用有限元计算方法研究腹杆偏心产生弯矩对空间相贯节点承载力的影响,对工程实际中经常发生的施工偏差情况下节点的安全性判断提出了建议。     

咸阳国际机场T3A航站楼屋盖圆管相贯节点试验研究

西安咸阳国际机场二期扩建工程T3A航站楼的钢结构屋盖节点形式采用构造复杂的空间加强套管相贯节点。由于节点构造复杂,不能简单按现行钢结构规范进行极限承载力计算,为考察节点的受力性能,对三个足尺试件模型进行试验研究,并运用有限元的方法进行分析。试验结果表明,试件的承载力均能达到SJ2c支管设计荷载水平的1.8倍以上,且试件无宏观破坏现象。试验和有限元分析结果证明,节点采取加焊套管的加强措施是有效的。     

基于微观断裂机制的XK型相贯节点极限承载力分析

采用基于微观断裂机制的空穴扩张模型（VGM）和应力修正应变模型（SMCS）对XK型相贯节点进行断裂预测,分析了有限元模型中考虑焊缝构型与否对断裂预测结果的影响。通过与试验结果的对比,证明了合理考虑焊缝构型在相贯节点断裂预测中的重要性,验证了VGM模型用于预测相贯节点在单调荷载作用下延性断裂的适用性。分析了XK型相贯节点在腹杆轴力作用下的破坏模式和极限承载力。结果表明,XK型相贯节点可能在受拉腹杆与弦杆之间的焊缝处发生断裂,这种破坏模式属于强度破坏,节点极限承载力应取该断裂荷载|XK型相贯节点也可能在受压腹杆与弦杆相交处因过大的塑性变形而破坏,此时,节点极限承载力应取荷载-弦杆变形曲线的峰值荷载。XK型相贯节点的破坏模式与节点几何构造和腹杆受力状态有关。     

空间阶梯肋环型钢屋盖多管相贯节点试验研究

江阴市民水上活动中心的屋盖钢结构采用了阶梯式肋环型钢管网格结构体系。对该屋盖体系中的多管汇交相贯节点进行足尺试验研究,系统地总结了试验过程中的若干关键问题,包括最不利节点荷载选取、加载装置设计、加载制度确定以及试件测点布置等。根据节点足尺试验结果,分析节点域在设计荷载下的应力分布、刚度变化以及极限承载力。为了与试验结果进行比较,进行了该节点在试验条件下的有限元数值分析,确定了节点的极限承载力,为结构设计提供了可靠的数据及建议,可为类似复杂空间钢结构多管相贯节点的结构设计或试验提供参考。     

内加劲环间距对X型圆管相贯节点性能的影响

为了研究内加劲环间距对X型圆管相贯节点性能的影响,对加劲环设置情况各不相同的4个X型相贯节点试件进行试验研究与有限元分析.介绍了试验方案、有限元模型,并对试验和有限元计算结果进行对比分析.结果表明:内加劲环的设置对X型节点受力性能有一定的提高;当位于主支管相贯范围内,内加劲环对节点的强度、刚度等受力性能的提高幅度较大;...     

高温下螺栓球节点受拉性能试验研究

为了研究空间网架结构螺栓球节点高温下的受力性能,通过18个螺栓球节点试件高温下的受拉试验,得到了不同温度下螺栓球节点试件受拉承载力。试验结果表明:高温下试件破坏截面均位于高强度螺栓螺纹处,温度低于400℃时,试件发生脆性断裂;温度不小于400℃后,试件破坏时的截面颈缩明显,发生延性破坏。随着温度升高,螺栓球节点试件的刚度、极限荷载逐渐降低;温度超过300℃后,节点试件刚度、极限荷载下降很快。根据试验数据拟合得到了螺栓球节点受拉极限荷载折减系数表达式。与已有的高温下高强度螺栓材料的受拉屈服强度和极限强度折减系数相比,螺栓球节点的相应折减系数更低。     

鞍板和环板加劲K形相贯节点承载力试验研究

为研究采用节点板、鞍板、环板加劲的K形相贯节点的受力特性,设计并制作了11个节点试件开展比例加载试验研究,得到其变形、应力分布及破坏模式等受力性能。利用经试验验证的有限元模型,分析了加劲组件和钢管参数对该类加劲相贯节点承载力的影响,并给出了受荷节点的力学模型。有限元分析和试验结果表明,该节点表现出无加劲相贯节点和带鞍板的管-板节点的受力特征,加劲构造能有效提高节点承载力。参数敏感性分析结果表明,增加支管和主管直径比、主管厚度、节点板长度和扇形鞍板圆心角可提高节点极限承载力。给出了极限承载力简化计算方法,计算结果和有限元分析及试验结果吻合较好。     

轴力下空间TK型圆钢管相贯节点的承载力分析

空间TK型圆钢管相贯节点在大跨度空间桁架中已得到广泛应用,但目前关于该节点极限承载力的计算方法尚不完善。本文在试验的基础上,对36个该类节点进行双重非线性有限元分析,计算其极限承载力并探索不同几何参数和加载方式对其的影响规律 同时借鉴平面K型圆钢管相贯节点承载力计算公式,考虑空间效应的影响,提出了空间TK型圆钢管相贯节点的承载力建议公式,经对相关试件进行计算,结果表明与试验结果吻合良好。     

Experimental and Numerical Study on Complex Multi-planar Welded Tubular Joints in Umbrella-Type Space Trusses with Long Overhangs

A test rig with multi-functional purposes was specifically designed and manufactured to study the behavior of multi-planar welded tubular joints subjected to multi-planar concurrent axial loading. An experimental investigation was conducted on full-scale welded tubular joints with each consisting of one chord and eight braces under monotonic loading conditions. Two pairs or four representative specimens (two specimens for each joint type) were tested, in which each pair was reinforced with two kinds of different internal stiffeners at the intersections between the chords using welded rectangular hollow steel sections (RHSSs) and the braces using rolled circular hollow steel sections (CHSSs) and welded RHSSs. The effects of different internal stiffeners at the chord–brace intersection on the load capacity of joints under concurrent multi-planar axial compression/tension are discussed. The test results of joint strengths, failure modes, and load–stress curves are presented. Finite element analyses were performed to verify the experimental results. The study results show that the two different joint types with the internal stiffeners at the chord–brace intersection under axial compression/tension significantly increase the corresponding ultimate strength to far exceed the usual design strength. The load carrying capacity of welded tubular joints decreases with a higher degree of the manufacturing imperfection in individual braces at the tubular joints. Furthermore, the interaction effect of the concurrent axial loading applied at the welded tubular joint on member stress is apparent.     

Strength of tubular welded joints of roof trusses in Shanghai Qizhong Tennis Center

Static strength of multi-planar welded joints with seven brace members and one chord member made of circular hollow sections is investigated in the paper, based on the engineering practice of moveable roof trusses of Shanghai Qizhong Tennis Center. Firstly, comparative experiments were carried out on two model joints with a scale of 1:3. One joint was not reinforced, whereas the other was reinforced with ring stiffeners inside the chord member. Failure mode, stress distribution, plastic-zone development and ultimate load capacity of the joints were investigated, and effects of the ring stiffeners on the joint behavior were observed through the experiments. Secondly, finite element analysis of both the tested model joints was performed. The calculation results are in a good agreement with the experimental results, which indicated that the numerical analysis was quite effective. Finally, the strategy for enhancing strength of the complicated joint is discussed. Parameters study on the constructional details of ring stiffeners was carried out using FE method. The present research shows the multi-planar circular hollow section joint with high ratio of diameter to thickness of the chord and multiple braces is liable to chord plasticity under axial tension and compression on the braces. For the design of the joint, it is suggested that the ring stiffeners are installed insider the chord to meet needs of enough stiffness and strength. Both position and number of the stiffeners should be carefully determined based on the axial forces on the braces and their diameters. The stiffener thickness should not be less than the chord thickness, and the diameter of the hole at the center of the stiffener should not be greater than half of the chord diameter.     

Strength of tubular welded joints of roof trusses in Shanghai Qizhong Tennis Center

Static strength of multi-planar welded joints with seven brace members and one chord member made of circular hollow sections is investigated in the paper, based on the engineering practice of moveable roof trusses of Shanghai Qizhong Tennis Center. Firstly, comparative experiments were carried out on two model joints with a scale of 1:3. One joint was not reinforced, whereas the other was reinforced with ring stiffeners inside the chord member. Failure mode, stress distribution, plastic-zone development and ultimate load capacity of the joints were investigated, and effects of the ring stiffeners on the joint behavior were observed through the experiments. Secondly, finite element analysis of both the tested model joints was performed. The calculation results are in a good agreement with the experimental results, which indicated that the numerical analysis was quite effective. Finally, the strategy for enhancing strength of the complicated joint is discussed. Parameters study on the constructional details of ring stiffeners was carried out using FE method. The present research shows the multi-planar circular hollow section joint with high ratio of diameter to thickness of the chord and multiple braces is liable to chord plasticity under axial tension and compression on the braces. For the design of the joint, it is suggested that the ring stiffeners are installed insider the chord to meet needs of enough stiffness and strength. Both position and number of the stiffeners should be carefully determined based on the axial forces on the braces and their diameters. The stiffener thickness should not be less than the chord thickness, and the diameter of the hole at the center of the stiffener should not be greater than half of the chord diameter. __________ Translated from Journal of Building Structures, 2007, 28(1): 36&2-42 [译自: 建筑结构学报]     

成都双流国际机场T2航站楼空间相贯节点极限承载力研究

以成都双流国际机场T2航站楼建设项目为背景,设计出一套空间自平衡加载装置,对工程中采用的2个复杂相贯节点进行足尺静力加载试验。在设计荷载作用下,节点处于弹性状态;在极限荷载作用下,主管发生明显变形,但节点极限承载力远高于设计荷载,失效模式表现为延性性质。同时,采用ABAQUS有限元分析软件对节点进行弹塑性非线性分析,将试验结果与计算结果进行对比分析,验证有限元模型的正确性;进一步探讨几种主管加劲肋形式对节点极限承载力的影响。研究表明,中心设置一块加劲肋最为有效,既能提高节点极限承载力,又具有较好的经济性和施工便捷性。     

Study on spatial effect of concrete-filled steel tubular KK-joints

为研究钢管混凝土空间相贯节点的空间效应,通过精细化有限元模拟对钢管混凝土空间相贯节点的受力性能进行了研究。建模时考虑了材料非线性、几何非线性、钢管与混凝土之间的接触非线性,建立了钢管混凝土KK形相贯节点的精确有限元模型,研究了空间效应对节点承载能力和破坏模式的影响。结果表明：钢管混凝土空间相贯节点的承载力远高于钢管空间相贯节点;钢管混凝土空间相贯节点和平面相贯节点的破坏模式相同,破坏模式有两种,一种是主管管壁冲剪破坏和受压支管屈服联合破坏,发生在支管管壁较薄的情况,另一种是主管管壁冲剪破坏;空间效应对钢管和钢管混凝土相贯节点承载力的影响不同,对于钢管混凝土相贯节点,支管空间夹角60°的节点承载力较平面节点有所降低,在设计时应该考虑空间效应的影响;空间效应对钢管混凝土空间相贯节点刚度影响不大。     

武汉火车站空间多平面圆钢管相贯节点承载力计算

对空间多平面圆钢管相贯节点承载力进行了研究,包括复杂多平面相贯节点的拆分原则、中外规范公式对比、多平面相贯节点承载力折减系数取值等,最后得出文中提出的复杂多平面相贯节点的拆分原则是合理的;采用欧洲规范对相贯节点进行校核偏安全;提出的多平面相贯节点承载力折减系数对武汉火车站工程是适用的。     

一种新型无内隔板梁柱节点有限元分析

采用有限元软件ANSYS,对根据实际工程加固中提出的新型无内隔板节点的极限承载力进行了进一步有限元研究,分析该类矩形钢管柱无内隔板梁柱节点在各加载阶段的位移变化和应力分布情况,考查其破坏形式,并比较了该类节点在不同梁柱截面尺寸下的极限承载力,得到该类节点极限承载力与梁柱尺寸的变化规律,为今后该节点的广泛工程应用提供参考依据。     

混凝土框架节点碳纤维布抗震加固新方法研究

提出了用碳纤维布加固平面框架中间节点和空间框架中间节点的新方法,通过5个框架中间节点(其中2个为假三维节点)的足尺拟静力试验,验证了本文加固方法的有效性。试验结果表明,对平面框架梁柱节点,在核心区水平及竖向粘贴碳纤维布,以及竖向和斜向交叉粘贴碳纤维布两种加固方法均能显著改善构件的延性,承载力也有一定的提高;对空间框架梁柱节点,采用碳纤维布与小钢架联合加固,不但能够大大提高构件延性,而且能够提高节点的屈服强度、极限强度和屈服后刚度,加固效果十分明显。基于试验结果,提出了节点加固的设计方法建议。     

空间KK型钢管—板节点受力性能分析

针对特高压输电塔结构空间KK型钢管—板节点进行非线性有限元分析,考查了节点的破坏模式和极限承载力。重点分析了腹杆加载比例、几何参数和主管应力比等对空间KK型钢管—板节点极限承载力的影响。结果表明,腹杆加载比例为正时,节点极限承载力随其增大而显著降低;腹杆加载比例为负时,其对节点极限承载力的影响不大;主管应力比对节点极限承载力的影响随腹杆加载比例的变化而对节点的受力性能形成复合影响效应。在此基础上,通过对数值结果的回归分析,并综合考虑各种因素对节点极限承载力的影响,提出了该类节点的极限承载力计算公式。