组合桁架节点的试验及有限元分析

采用模拟试验及有限元方法,对某桁架斜拉桥中组合节点的力学性能进行分析。试验研究了此节点的安全裕度及适用性,模型缩尺比例为1:2.5。分析了应力分布、裂缝抵抗能力、锚栓剪切抵抗力,研究了节点的力学性能及传力途径。在荷载达到设计荷载的1.7倍前,钢板和混凝土弦杆的最大应变均在弹性范围内,说明这种结构有很好的安全裕度。基于试验结果,建立三维有限元模型,有限元分析的承载力和刚度计算结果与试验吻合较好。本分析为后续研究及组合桁架桥、组合节点的设计,提供了有价值的参考。     

大跨度钢-混凝土组合桁架铁路桥端节点模型试验研究

钢-混凝土组合桁架梁上弦端节点受力复杂,有必要通过模型试验对其钢-混上弦节点的应力应变状态及工作性能进行研究,探索组合桁架上弦节点合理构造和承载力。介绍节点模型的设计、加载过程和测点布置等;重点通过对试验结果分析和有限元计算的比较,得出弦杆应变和节点板应力的分布规律,通过绘制弦杆荷载-水平位移曲线,对节点的非线性受力行为进行研究,得出节点整体的受力性能。研究表明:钢-混凝土组合桁架节点受力合理,节点承载力安全储备较高,满足铁路桥梁设计要求,PBL连接件抗剪能力良好;节点板是受力的关键部位,加设节点板加劲肋可以有效提高节点屈服后强度,但对极限荷载的提高作用不大。     

钢桁架桥静力分析及地震荷载响应分析

在有限元分析软件ANSYS环境下,对建立的有限元模型某钢桁架桥的桥体在静力的作用下进行节点的位移分析。同时,在该桥体侧向施加地震谱,分析该结构的地震荷载响应,并得出一些结论。     

Experimental and numerical study on restrained composite slab during heating and cooling

In this paper, a series of fire tests on restrained composite slabs, carried out at the University of Manchester, is presented. A total of six composite slabs were tested under different fire scenarios, with different load ratios. The tests were particularly concerned with the variation of internal forces within the slabs during both heating and cooling phases. In addition to the testing programme, two separate nonlinear finite element models have been developed to simulate the thermal and mechanical behaviour of composite slabs during heating and cooling, which is introduced in detail in this paper. In the thermal analysis model, plane elements were adopted to obtain a detailed thermal behaviour. In the structural analysis model, the concrete, steel deck and mesh were simulated by solid elements, shell elements and truss elements respectively. The interaction between the concrete and steel sheet was simplified to spring elements. According to the experimental results and FE modelling, the behaviour of composite slabs was analysed in detail. At last, the parametric study was performed where the effect of concrete strength, steel deck thickness and mesh size was analysed.     

钢桁架连梁节点锚固机理试验及有限元分析

为了揭示钢桁架连梁节点的受力机理,基于6个钢桁架连梁节点试验研究,对考虑混凝土损伤塑性模型的钢桁架连梁节点进行了非线性有限元分析,通过改变锚固长度和型钢型号,对比数值仿真与试验结果发现吻合较好。分析结果表明:有限元模型所得的节点处弦杆的应变分布规律与试验结果一致。在其他情况不变时,节点开裂荷载随着锚固长度的增加而增大;当锚固长度达到一定长度时,节点处弦杆端点的应变接近于零。     

刚接和铰接钢桁架静动力特性分析

采用结构力学方法对刚接和铰接桁架的内力和变形进行了比较,采用ANSYS有限元软件对以上两种桁架的静动力特性进行了分析（模态分析）,得出两种桁架在静力特性方面（内力和变形）相差不大,而在动力特性方面却相差较大的结论。     

1-64m客货共线钢桁架桥荷载试验及数据分析

对某1-64 m客货共线钢桁架梁桥进行了荷载试验及数据分析研究,提出了该桥荷载的试验方法,并进行了该桥静动载试验研究,通过计算模拟分析了最不利荷载作用下该桥的受力响应,得出该试验桥梁的受力性能和正常使用状态承载能力满足设计荷载等级要求的结论。     

空间连续组合桁梁桥有效分布宽度分析

通过对某两跨空间连续组合桁架梁桥的有限元模拟,分析了均布荷载和集中荷载作用下该桥面有效分布宽度,继而探讨了宽跨比、桥面板厚度、高跨比,以及节点纵、横桥向间距等参数变化对桥面板有效分布宽度的影响,最后与各国规范进行有效分布宽度系数的对比,得出空间连续组合桁架梁有效分布宽度的规律。     

钢管桁架焊接节点的抗弯性能研究综述和分析

分析了钢管桁架焊接节点的特点,介绍了国内外对由钢管直接焊接而成的钢管桁架节点的抗弯工作性能的研究状况,并提出了今后应重点研究的几个问题,以促进钢管桁架的研究。     

梭形钢屋架中张弦梁与管桁架方案的对比分析

用有限元方法分析了张弦梁和管桁架结构在梭形钢屋架设计中的力学性能,并对比了经济指标,指出在跨度不大的情况下,设计合理的管桁架的建造费用与张弦梁基本相等,并且避免了施工过程中的找形困难和预应力张拉的施工步骤,是个值得考虑的方案。     

钢管—混凝土组合桁架结构的静力分析

提出了钢管—混凝土组合桁架形式,为研究该类结构的静力特性,对组合桁架与普通桁架分别建立有限元分析模型,并应用ANSYS对其进行了对比分析。研究结果表明,组合桁架的内力分布均匀,能较好的发挥材料强度,具有抗弯刚度大的特点;对两端简支的组合桁架,其两端腹杆轴力较大,跨中腹杆轴力较小(几乎为零),与实腹梁受剪性能相似;下弦杆受拉,上弦混凝土板代替上弦杆受压,能充分利用混凝土受压和钢材受拉的材料性能。     

Seismic behavior of CFRSTC composite frames considering slab effects

This paper reports on an experimental and numerical investigation conducted on the seismic behavior of concrete-filled rectangular steel tubular columns (CFRSTC) composite frames. The experimental study was conducted by subjecting two full-scale composite frames to simulated seismic loads. Both frames were composed of CFRSTC and steel beams. One specimen was placed on a reinforce concrete (RC) floor slab and the other was not. The purpose of the test was to investigate the elasto-plastic performance of the CFRSTC composite frame system and to examine the effects of composite action on the behavior of composite frames. The test results showed that the stiffness, strength and energy-dissipating capacity of the CFRSTC frame increased significantly with the presence of the floor slab. Compared with a bare steel beam, the composite beam experienced a decrease in the rotation capacity from 0.046 rad to 0.026 rad. The shear deformation of the panel zone grew because of the composite action, which delayed the fracture of the beam. Finite element (FE) models were established to simulate the tested frames. The results of the FE model fit well with that of the test model in terms of stiffness, strength, hysteretic behavior and component deformation.     

钢管桁架结构大间隙焊缝相贯节点性能试验与理论研究

河南艺术中心艺术墙与屋面钢结构均采用钢管相贯桁架结构体系。复杂建筑几何造型、运输变形、焊接变形、安装误差等多方面因素,使钢管相贯节点处腹杆相贯线与弦杆间隙远超过规范要求。为解决大直径、相贯线大间隙焊缝的圆钢管相贯节点安全问题,选定2个节点制作足尺试件进行试验研究,相贯线处间隙取30mm并按拟定的焊接工艺施焊;建立节点三维实体有限元模型进行弹塑性有限元分析;通过对比分析,确认工程大直径钢管、大间隙相贯节点的安全性,同时验证了规范公式及有限元分析方法对该类节点设计的适用性,对钢管相贯节点承载力(破坏)判定准则进行了探讨。     

大跨度叠合梁斜拉桥计算分析

运用桥梁有限元分析软件MIDAS Civil,分别采用等效截面、联合截面和普通截面方式模拟叠合梁截面,对某一双塔叠合梁斜拉桥进行分析计算,并对比计算结果得到结论,可为其他斜拉桥叠合梁有限元分析提供借鉴。     

The unilateral contact problem in composite slabs: Experimental study and numerical treatment

The shear connection between concrete and profiled steel sheeting in composite slabs is a highly nonlinear problem as far as boundary conditions, material and geometry are concerned. It can be treated as a unilateral contact problem where sticking, sliding and frictional phenomena at the interface of the bodies are all present. Unilateral contact problems, where the contact and noncontact regions between bodies or structures are not a priori known, can be described by the use of nonmonotone material laws. This leads to a hemivariational inequality, which describes the problem under consideration mathematically. The study is also extended experimentally and numerically. The results of both analyses are presented and compared.     

梯形钢屋架静动力分析

在ANSYS环境下采用弹性分析建立有限元模型对屋架进行静力和水平地震波作用分析,对其在静力作用下进行了内力及变形的分析,同时,对其在水平地震波作用下的最大位移进行了分析并得出一定的结论。     

Time analysis of composite beams with partial interaction using available modelling techniques: A comparative study

This paper presents a comparison of available numerical structural formulations for the short- and long-term analysis of composite beams with partial shear interaction. The finite difference method, the finite element method, the direct stiffness method and the exact analytical model have been considered, and both the instantaneous analysis and the time analysis based on the age-adjusted effective modulus method (AEMM) have been carried out. For modelling based on the first two of these formulations, a spatial discretisation and a discretisation in the time domain are required, while only the time discretisation needs to be specified for the direct stiffness method. The results obtained using these formulations are compared qualitatively and their accuracy is estimated, adopting the exact analytical model as a benchmark reference with the objective of establishing the minimum spatial discretisations required to keep the error within an acceptable tolerance. These comparisons are carried out for simply supported beams, propped cantilevers and fixed ended beams, from which the qualitative behaviour of these formulations in the modelling of continuous beams can also be deduced.     

有限元分析在圆环桁架内支撑形中的运用

结合工程案例采用二维模型对圆环桁架支撑受力计算方式进行了探讨,将计算结果与监测结果进行对比,得出计算结果比监测结果小的结论,指出将计算结果用于支撑构件设计时应考虑适当增加安全系数。     

方管桁架节点分析和计算方法综述

通过对相关文献研究,以国家体育馆桁架K形节点为例,对方管桁架节点的分析和计算的各种方法进行了比较和总结,以期为工程计算和分析提供指导。