共查询到19条相似文献,搜索用时 203 毫秒
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正在建设的国家体育场两两斜交的主桁架构成了许多双弦杆焊接方管KK型节点,该节点连接焊缝密集,构造极其复杂。本文对这种在管结构中较为独特的节点进行了1∶4的缩尺模型承载力试验研究,详细介绍了节点的试验方法和结果,讨论了节点的受力性能、破坏模式以及节点内部加劲肋的作用。研究表明该节点的构造措施较完善可靠,节点具有较高的承载力。节点的薄弱部位处在受压腹杆端部,发生局部屈曲。弦杆内部纵横向加劲肋的设置有效地增强了节点强度和刚度。腹杆端部的局部放大改善了腹杆向弦杆的传力,降低了应力集中。 相似文献
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空腹钢管桁架内加劲节点抗弯性能试验研究 总被引:2,自引:1,他引:1
上海市某工程中采用了内设加劲肋的箱形截面弦杆与方钢管腹杆直接焊接形成的空腹桁架节点.为考察此类节点在平面内弯矩作用下的静力承载性能,分别进行了腹杆根部有无纵肋的2个对比试件的模型试验和有限元分析.试验结果表明,该类型节点的破坏模式为腹杆根部受拉侧翼缘与弦杆连接焊缝开裂、节点域剪切变形、腹杆受压翼缘局部屈曲等形式;增设纵肋可以阻止腹杆根部受压翼缘局部屈曲的发生,并使节点域腹杆翼缘上沿杆轴方向的应力分布更均匀,但是该措施降低了节点的变形c能力.与无加劲节点承载力公式值比较结果表明,该类节点的承载力有显著提高. 相似文献
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最近建设完成的京沪高速铁路上海虹桥站结构中,有一种钢桁架-钢管混凝土柱焊缝连接的新型节点,该节点构造和受力性能极其复杂。本文对该节点进行了1∶4缩尺模型承载力试验研究,介绍了如何实施对该复杂节点加载的试验方法,讨论了节点的受力性能、薄弱环节和破坏模式。试验表明该节点构造设计有效,具有足够的承载力,可达到设计荷载的3倍,并具有良好的塑性变形能力。但是,节点也显示出薄弱坏节,表现为在钢桁架受拉斜腹杆翼缘与节点环板竖向加劲肋的焊接部位出现开裂现象。建议适当增大受拉斜腹杆端部的翼缘弯折曲率半径,平缓腹杆向竖向加劲肋的传力,可使节点性能得到进一步完善。 相似文献
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结合国家体育场大跨度钢结构设计,提出任意角度相交焊接方管桁架双弦杆KK节点的几何构型方法,可用于各种复杂角度的腹杆汇交、弦杆呈折线形、弦杆侧壁与腹杆侧壁不垂直等多种情况,适用范围较大。通过调整节点域板件的角度,改善其构造的合理性。综合采用调整板厚、设置加劲肋等措施,提高节点的承载力,实现“强节点”的设计理念。双弦杆KK节点的缩尺模型试验表明,试件的应力分布与有限元计算非常接近,节点具有较大的安全储备。 相似文献
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为研究低层冷弯薄壁型钢结构屋架的受力性能,对两个不同构造形式的屋架足尺试件进行了受弯性能试验研究,考察了冷弯薄壁型钢结构屋架的工作原理和破坏模式。试验结果表明:钢桁架的破坏主要是支座处节点连接的破坏,而杆件没有发生屈曲,不属于强度破坏。采用非线性有限元分析方法对钢结构屋架进行了变参数分析,结果表明:钢材强度、截面形式以及钢材厚度对桁架承载力都有较大的影响。采用柱挠度曲线(CDC)法分析了节点连接半刚性对冷弯薄壁型钢桁架压杆计算长度的影响,研究表明,冷弯薄壁型钢桁架压杆半刚性连接的计算长度与节点转动刚度和构件自身刚度有关,建议受压弦杆、端斜腹杆以及端竖腹杆平面内计算长度系数取为1.0,受压腹杆平面内计算长度系数取为0.9。 相似文献
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KT型相贯节点承载力有限元及设计方法分析 总被引:1,自引:0,他引:1
对KT型圆钢管空间相贯节点的极限承载力进行非线性有限元分析,揭示KT型相贯节点的受力性能。结果表明:在支杆轴力大小不同的情况下,随着支杆与弦杆直径比角、腹杆与弦杆直径比屉、支杆与弦杆厚度比τ1、腹杆与弦杆厚度比τ2和弦杆径厚比γ的变化,节点发生弦杆局部屈曲模式、腹杆轴向屈曲破坏和支杆强度破坏3种破坏模式;有焊缝的加强作用,节点承载力有所提高;分析支杆与腹杆轴力不同比值情况下的节点承载力,提出KT型节点承载力简化设计公式。 相似文献
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TONG Lewei GU Min CHEN Yiyi ZHOU Liying SUN Jiandong CHEN Yangji LIN Yingru LIN Gao 《Frontiers of Structural and Civil Engineering》2008,2(1):30
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. 相似文献
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以上海旗忠网球中心可开闭屋盖支座节点为工程背景,探讨了由7根支管和1根主管焊接而成的复杂空间多支管节点静力强度。首先进行了两个1∶3的缩尺模型节点静力对比试验,一个节点的主管中不设置加劲板,另一个节点在主管内设置了环向加劲板。试验研究了节点的破坏模式、应力分布、塑性发展、承载能力,观察了加劲板对节点性能的影响。其次,应用有限元方法对两个所试验的模型节点受力性能进行了数值分析,将计算结果与试验结果作了比较,表明有限元数值分析有效可靠。最后,讨论了增强复杂管节点强度的措施,进行了环向加劲板构造参数的有限元分析。研究表明主管径大壁薄、多支管的空间圆管节点在支管有拉有压的情况下很容易发生主管屈服破坏,设计时建议在主管内布置环向加劲板来保证节点刚度和强度,须根据支管轴力大小、拉压性质、支管与主管相交位置等因素来精心设计加劲板的位置和数量。加劲板的厚度不宜小于主管的壁厚,加劲板中心开孔的直径不宜大于0.5倍的主管直径。 相似文献
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Lewei TONG Min GU Yiyi CHEN Liying ZHOU Jiandong SUN Yangji CHEN Yingru LIN Gao LIN 《Frontiers of Architecture and Civil Engineering in China》2008,2(1):30-36
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.
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Translated from Journal of Building Structures, 2007, 28(1): 36&2-42 [译自: 建筑结构学报] 相似文献
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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. 相似文献
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Although several studies of the out-of-plane strength and design of steel arches with a solid web section have been reported, little research of the out-of-plane strength and design of spatially trussed arches has been reported in the open literature or design codes. In deference to the steel arch with a solid web section, the shear deformations play important parts in the out-of-plane inelastic buckling behavior of spatially trussed arches. In addition, global out-of-plane inelastic buckling of a spatially trussed arch is associated with local buckling of its components such as chord and diagonal web tubes and hence local component buckling influences the out-of-plane strength of the arch. This paper investigates the out-of-plane inelastic strength and design of spatially trussed circular arches with a rectangular lattice section under general loading using a three-dimensional nonlinear inelastic numerical approach. Methods for the out-of-plane inelastic strength and design of spatially trussed arches under uniform compression or under uniform bending are developed, based on which interaction equations for the design of spatially trussed steel arches under general loading against their out-plane failure are proposed. These interaction equations provide good lower bounds for the out-of-plane strength of spatially trussed arches. 相似文献
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苏州火车站屋盖结构采用空间菱形大跨度钢管桁架结构,局部为双向交叉菱形桁架。桁架汇交杆件数量多、直径大,节点构造非常复杂。工程节点主要采用相贯焊接的形式,受力集中和几何构型非常独特的部位采用铸钢节点。焊接节点域进行局部加厚,并在主通弦杆内部设置环形加劲肋,以提高节点承载力。铸钢节点域根据构件的几何尺寸与空间关系确定主通杆件与加劲肋的设置方式,采用渐变壁厚的方式满足受力平衡过渡以及铸造工艺的要求,并在构件端口设置构造环肋以及反向焊接坡口解决与钢管的连接。通过有限元分析与试验研究对上述节点构造的合理性进行了全面分析,确保节点具有较大的安全储备。 相似文献
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Local buckling behaviors of box section with various stiffeners subjected to compressive load. An analytical procedure for the elastic local buckling problems of box‐section with open, closed and L‐type stiffeners by the extended matrix method is presented. An exact solution can be obtained by treating the compressive box‐section with stiffeners as the branching panels in the transfer matrix method. The results are given as two local buckling behaviors. The first local buckling behavior is the local buckling shape to become a joint at the position of the each stiffener, and the second local buckling behavior is the local buckling shape of individual plate to compose box‐section. 相似文献
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通过12根腹板开孔复杂卷边槽钢和Σ形复杂卷边槽钢双肢拼合工字形简支轴压构件的轴压试验,研究了构件承载能力、失稳模式和拼合作用。采用有限元软件ANSYS对试验进行了模拟,验证了分析模型准确性。并通过有限元变参数分析研究了孔高、孔宽和孔间距对拼合构件承载力的影响。结果表明:复杂卷边槽钢截面双肢拼合开孔构件的腹板多波失稳现象明显,屈曲发生时两腹板间的相互支撑作用较强;Σ形复杂卷边槽钢截面双肢拼合开孔构件能有效地控制腹板局部屈曲的发生并显著提高短柱、中长柱的承载力;设置腹板加劲肋有助于提高孔洞周围板件变形的约束作用,同时也减弱了两单肢腹板间的相互支撑作用;相同条件下,Σ形复杂卷边槽钢截面双肢拼合开孔构件的轴压承载效率与复杂卷边槽钢截面双肢拼合开孔构件相比,短柱提高了32%,中长柱提高了10%,长柱提高了2%;非加劲截面构件在不同长度下,孔高为腹板高度1/2(69 mm)时构件的稳定承载力较孔高为25 mm时下降约7%;而孔宽、孔间距对上述两类截面构件稳定承载力影响不大;此外,采用直接强度法预测非加劲截面双肢拼合构件的承载力结果偏于保守,而对加劲截面双肢拼合构件则略显不安全。 相似文献