天津奥林匹克中心体育场铸钢节点试验研究

天津奥林匹克中心体育场大跨度钢管桁架结构铸钢节点受力和构造复杂,为考察铸钢节点的受力性能,评价其安全性,对铸钢节点进行了足尺试验和有限元计算分析。首先建立节点有限元实体模型进行有限元计算分析;根据有限元计算结果,布置应变测点,对节点进行设计荷载作用下的试验,得到节点应力试验值。结合试验结果与有限元计算结果,分析了节点的应力分布规律,表明天津奥林匹克中心体育场铸钢节点具有较高的承载性能和足够的安全性。     

方钢管混凝土柱-穿筋钢梁节点有限元分析

基于大型有限元分析软件ABAQUS,研究在低周反复荷载作用下新型钢管混凝土结构节点——方钢管混凝土柱与钢梁的穿筋节点的力学性能,并将计算值与试验值进行对比,验证非线性分析方法的有效性。建立同时考虑几何非线性、材料非线性的有限元分析模型,分析在低周往复荷载下该节点的破坏模式、承载力、延性及耗能能力等。计算值与试验值吻合度较高,验证了有限元分析模型的准确性,并进一步分析了该节点的力学性能。计算结果发现滞回曲线饱满,位移延性系数理论值介于3.79~4.91,耗能比理论值均大于0.9。新型穿筋节点传力路径明确,延性及耗能能力较好,有限元分析模型能够较好地模拟该节点的力学性能,为进一步研究和改善该节点提供更方便、经济的方法。     

全装配式外套筒-加强式外伸端板组件梁柱连接节点抗弯承载力研究

提出全装配式外套筒-加强式外伸端板组件梁柱新型连接节点,通过理论分析、试验研究和有限元分析,确定了节点受力计算模型,推导出节点抗弯承载力理论计算式,并与有限元模拟值和试验结果进行比较,三者吻合较好,证明其具有合理性和良好的适用性。所提出的节点抗弯承载力计算方法可为该类节点的设计和计算提供理论工具。试验研究与有限元分析还表明,装配式外套筒-加强式外伸端板组件梁柱连接节点的屈服机制为:外套筒和柱壁内凹受压屈曲、外伸端板压屈、节点屈服;梁柱连接节点具有良好的耗能能力,增大外套筒厚度,节点屈服荷载增加,耗能能力提高。     

新型方钢管混凝土柱梁节点有限元分析

结合现行钢管混凝土柱在实际工程中的应用情况,提出了用于方钢管混凝土柱—钢筋混凝土梁框架结构的新型节点连接形式——非穿心暗钢牛腿方钢管混凝土柱与混凝土梁节点,利用有限元软件ANSYS对该节点的力学性能进行了分析,并与试验结果进行了比较,计算结果表明:有限元计算模型适用于该类型节点的分析,从计算和试验两方面均得出新型钢管混凝土节点满足强柱弱梁、节点更强的原则。     

上海铁路南站外柱异形铸钢节点承载性能研究

对上海火车南站站屋结构外柱铸钢节点的受力性能进行相关研究,制定足尺试验和有限元数值分析结合、相互验证的研究方案.针对节点体型复杂、尺寸重量庞大、不易加载等特点,设计出自平衡加载系统;同时为解决实际工作中节点受力面的非理想状态,考虑不同加载情况.建立铸钢节点的数值模型,利用有限元分析模拟节点在试验荷载下的受力性能.数值模拟的结果在试验设计阶段对测点布置起指导作用;足尺试验可以得到铸钢节点表面的应力测试值,通过比较铸钢节点表面实测值和相应测点分析值,对应力实测值和计算分析值进行相互印证.在实测值与计算值符合较好情况下,由有限元计算结果推断节点内部应力分布.最后对铸钢节点在整个结构体系中的承载性能和安全性做出了评价.     

新型穿心钢筋暗牛腿钢管混凝土梁柱节点动力性能研究

提出了一种新型的圆钢管混凝土穿心节点,并介绍了该种节点在低周反复荷载作用下的试验结果,用AN-SYS软件建模进行有限元分析。试验结果与有限元计算相对比,二者吻合良好。试验结果表明:这种新型穿心节点承载力高、抗震性好、构造简单、受力明确,有广泛的工程应用前景。     

随州南站新型分叉节点受力性能试验研究

随州南站的树状结构采用一种新型非铸钢的分叉节点。此类分叉节点外形不规则、受力复杂。为研究此新型分叉节点在最不利设计工况下的受力性能,并验证其安全性和合理性,对节点进行有限元分析和足尺试验研究。节点模型的试验值与有限元分析结果吻合良好,表明此节点有限元模型能真实模拟节点模型的边界条件和受力状态。试验结果表明:足尺节点能够满足设计承载力要求;在1.3倍设计荷载作用下,节点主肢角部出现塑性发展区。根据分析结果对分叉节点设计进行改进,提高节点的安全冗余度。该新型分叉节点具有较高的安全储备。     

空间钢网壳大型铸钢节点结构实体试验研究

通过重庆奥林匹克中心体育场钢网壳罩棚大型铸钢节点足尺模型整体受力试验，得到铸钢节点及汇交杆件的应力大小测试值；通过理论分析及空间仿真计算，得到测点位置的应力分析值。将试验结果和有限元分析值对比分析，全方位了解铸钢节点的应力大小及分布情况；评价钢网壳节点的强度是否满足设计要求；对钢网壳节点的设计和施工工艺提出建议。     

新型连接件的叠合板组合楼盖边柱节点有限元分析

文中利用abaqus对采用新型不抗剪开孔钢板抗拔连接件的叠合板组合楼盖边柱节点进行有限元研究分析,并将有限元计算结果与试验结果和栓钉连接件的节点模拟结果进行对比。结果表明,有限元模型能较好的模拟试验情况,试验的破化形态与有限元分析基本一致,对比栓钉节点模拟结果,可以知道采用此新型不抗剪开孔钢板抗拔连接件可以有效的减缓负弯矩区混凝土开裂。后续可以在此模型的基础上开展进一步的研究分析。     

装配式可更换混凝土框架节点非线性分析

对可更换新型混凝土框架梁柱节点的抗震性能进行仿真研究,采用有限元软件ABAQUS对节点进行非线性有限元分析,介绍了混凝土和钢结构的本构模型、混凝土与混凝土界面特性、混凝土与钢结构之间的黏结特性.将有限元计算结果与试验数据进行对比,发现数值模拟结果与试验数据吻合良好.基于所建立的有限元模型对节点进行参数化分析,结果表明混...     

钢环加固圆钢管混凝土柱-RC梁角节点轴压性能有限元分析

针对圆钢管混凝土柱-RC梁角节点,提出了对角节点的节点区采用多段钢环加固的构造方案,并对加固节点模型的轴压性能开展有限元分析研究。通过已有研究成果验证了有限元模型分析方法的可靠性,继而采用ABAQUS有限元分析软件建立152个加固节点模型进行轴压试验模拟。有限元分析结果表明,以多段钢环加强的圆钢管钢筋混凝土柱-RC梁角节点轴压性能优于普通节点,加固节点具有更高的轴压承载力和更好的延性,加固效果明显。参数分析表明：加固角节点的轴压承载力随节点混凝土轴心抗压强度、节点区钢环体积占比和节点区纵筋配筋率的增加而增加;角节点的轴压承载力受梁端剪力影响,较大的梁端剪力可能造成节点延性降低。根据分析结果,建立了节点区采用钢环加固的圆钢管约束混凝土柱-RC梁角节点的轴压承载力算式,供设计该类节点参考。     

哈尔滨会展体育中心屋架铸钢节点性能研究

简述了哈尔滨会展体育中心张弦桁架的铸钢节点的构造和设计情况,进行了该铸钢节点的足尺静力试验和有限元分析。详细讨论了试验的加载装置、测试结果和有限元数值计算结果,给出了节点的应力分布状况。研究表明,该铸钢节点在设计荷载的作用下,具有足够的强度和刚度;有限元计算结果与试验实测结果基本吻合,前者也能够较好地了解铸钢节点的受力性能。最后对铸钢节点的制造质量也提出了建议。     

Stress and strain concentrations of completely overlapped tubular joints under lap brace OPB load

The stress and strain concentrations of a completely overlapped tubular joint specimen are experimentally investigated under lap brace out-of-plane bending (OPB) load. The experimental results showed that the strain distribution near the weld toe is fairly linear. The maximum strain concentration factor of the joint occurs at the through brace saddle near the lap brace. For the finite element (FE) analysis, both 8-node thick shell and 20-node solid elements are suitable for modelling the joint specimen. A set of parametric equations is proposed for predicting the stress concentration factor (SCF) of completely overlapped tubular joints based on 5184 FE models. The parametric equations are verified against the acceptance criteria of Fatigue Guidance Review Panel. The assessment of the proposed equations is based on the database of FE analysis and test results. The comparison of SCF showed that the existing T/Y-joint parametric equations for predicting the SCF of completely overlapped tubular joints are inappropriate under OPB load.     

Stress and strain concentration factors of completely overlapped tubular joints under lap brace IPB load

This paper presents parametric equations to predict the stress concentration factor (SCF) of completely overlapped tubular joints under lap brace in-plane bending (IPB) load. A completely overlapped tubular joint specimen is first tested for the verification and calibration of finite element (FE) models. The experimental results showed that the strain distribution near the weld toe is fairly linear. The maximum strain concentration factor (SNCF) of the joint occurs at the lap brace crown heel under IPB load. For the FE analysis, both 8-node thick shell and 20-node solid elements are suitable for modelling the joint. A set of parametric equations is proposed for predicting the SCF of completely overlapped tubular joints based on 5184 FE models. The parametric equations are verified against the acceptance criteria of Fatigue Guidance Review Panel. The assessment of the proposed equations is based on the database of FE analysis and test results. The comparison of SCF between the proposed parametric equations and the existing T/Y-joint parametric equations showed that the results do not agree reasonably well under IPB load.     

Surface wave propagation effects on buried segmented pipelines

This paper deals with surface wave propagation(WP) effects on buried segmented pipelines. Both simplified analytical model and finite element(FE) model are developed for estimating the axial joint pullout movement of jointed concrete cylinder pipelines(JCCPs) of which the joints have a brittle tensile failure mode under the surface WP effects. The models account for the effects of peak ground velocity(PGV), WP velocity, predominant period of seismic excitation, shear transfer between soil and pipelines,axial stiffness of pipelines, joint characteristics, and cracking strain of concrete mortar. FE simulation of the JCCP interaction with surface waves recorded during the 1985 Michoacan earthquake results in joint pullout movement, which is consistent with the field observations. The models are expanded to estimate the joint axial pullout movement of cast iron(CI) pipelines of which the joints have a ductile tensile failure mode. Simplified analytical equation and FE model are developed for estimating the joint pullout movement of CI pipelines. The joint pullout movement of the CI pipelines is mainly affected by the variability of the joint tensile capacity and accumulates at local weak joints in the pipeline.     

空间隔板焊接X形圆钢管相贯节点受力性能试验研究

对3个足尺空间隔板焊接X形圆钢管相贯节点分别进行了轴力作用下的单调加载试验和往复加载试验,得到了节点的破坏模式,并对节点的受力性能包括静力弹性刚度、承载力、延性和滞回性能等进行分析。验证了该种空间隔板焊接节点的构造措施合理,节点的承载能力相对设计工况有两倍以上的安全储备,节点受力安全可靠。运用ABAQUS软件建立有限元分析模型,并与试验结果对比,验证了有限元模型的适用性,并对节点进行设计工况下的内力校核,参数分析结果表明,管径厚比、相贯角度、椭圆连接板厚度及平面外角度对空间隔板焊接节点性能影响较大,节点刚度和承载力随着支管径厚比和平面外角度的增大而降低,随着相贯角度和椭圆连接板厚度的增大而提高。综合试验和有限元分析结果,节点设计要确保支管设计内力不大于节点承载力,增大椭圆板厚度以及补焊椭圆板隐藏焊缝对节点的受力性能改善较好;当设计该类较小相贯角度（小于20°）的节点时,需按节点承载力进行设计,同时考虑轴向刚度对节点受力性能的影响。     

K6型铝合金板式节点网壳稳定承载力设计方法

凯威特K6型是铝合金板式节点网壳最为常见的形式,而板式节点是一种典型的半刚性节点,其节点刚度对网壳整体稳定承载力的影响不可忽略。通过ANSYS有限元软件建立了K6型铝合金板式节点单层球面网壳数值模型,采用非线性弹簧单元COMBINE 39引入节点半刚性的影响,并基于该数值模型对网壳的弹塑性整体稳定承载力进行了参数分析。分析结果显示,网壳整体稳定承载力随矢跨比、环数、节点刚度的增大而提高,随跨厚比、半跨活荷载系数、初始几何缺陷幅值的增大和材料非线性的引入而降低。通过对8000多个数值模型的分析结果进行统计回归,得到了K6型铝合金板式节点网壳弹塑性整体稳定承载力计算式,该计算式能较准确地预估无缺陷网壳的稳定承载力。     

节理岩体两种模式的数值分析

采用节理单元和复合本构模型,对节理岩体进行有限元模拟,分析比较了两种模式的数值结果     

铝合金板式节点网壳稳定承载力试验研究

为研究铝合金板式节点刚度对单层球面网壳整体稳定性能的影响,制作一个跨度为8m、矢高为0.5m的K6型网壳模型,对网壳顶点施加4次单向循环荷载。试验结果表明,加载初期网壳表现出超刚性特征,即其刚度大于刚接节点网壳刚度;而后的节点螺栓滑移变形会降低网壳刚度,螺栓滑移引起的网壳变形很大且不可恢复。网壳的失稳属于整体跳跃失稳,但网壳屈曲后可继续承载,且荷载可进一步增大。最后一次单向循环加载时网壳因顶点杆件下翼缘的拉裂而破坏。另外,随着循环荷载逐级增大,网壳再加载初始刚度都有一定弱化。采用ANSYS有限元软件建立网壳分析模型,采用BEAM 188单元和COMBINE 39单元模拟考虑节点半刚性的铝合金板式节点网壳杆件,节点弯矩-转角关系曲线采用四折线模型,有限元分析结果与试验结果吻合较好。     

Parametric equations for stress concentration factors in completely overlapped tubular K(N)-joints

This paper presents parametric equations to predict the stress concentration factors (SCF) of completely overlapped tubular K(N)-joints under lap brace axial compression. 192 finite element (FE) models of the joint have been created for the parametric study using a commercial FE package, MARC. In the analysis, both 8-node thick shell and 20-node solid elements are found suitable for modelling the joint. The comparison of strain concentration factors (SNCF) between the FE models and the tested specimen shows that the difference is less than 0.42. However, in view of the computational effort, the FE model with 8-node thick shell element is used for the parametric analysis. The study reveals that the effect of through brace to chord wall thickness ratio on SCF of the joint is most crucial. The maximum SCF occurs on the through brace saddle near the lap brace. The gap size on the through brace surface between the outer surfaces of the chord and the lap brace significantly affects the SCF. Based on the FE data, a set of parametric equations is derived to predict the SCF of the joint. The reliability of the equations has been verified against the requirement of the Fatigue Guidance Review Panel.