福州长乐国际机场T2航站楼钢结构设计中的关键问题剖析

福州长乐国际机场T2航站楼主体采用钢筋混凝土框架结构,屋盖结构及支承系统采用钢结构,航站楼屋盖钢结构分为5个分区,中心区部分屋盖支承结构由锥形分叉柱和锥形钢管柱组成,指廊由钢管柱和幕墙柱支承。屋面为自由曲面,屋盖结构为桁架结构体系,由三角形立体桁架和平面桁架组成,屋面围护系统采用铝合金直立锁边金属屋面,外墙围护系统为玻璃幕墙。介绍了福州长乐国际机场T2航站楼屋盖钢结构的结构体系,对屋盖结构和支承结构在抗震性能目标下的承载能力进行研究,并对中心区屋盖钢结构的非线性稳定承载力和抗连续倒塌能力做了细致的研究,以确保航站楼结构在各种工况作用下是安全可靠的。

双层钢板-内填混凝土组合剪力墙整体稳定性分析

考虑几何初始缺陷和材料非线性,对带钢管混凝土端柱的双层钢板-内填混凝土组合剪力墙进行有限元弹塑性整体稳定性分析,研究高度、宽度、厚度、钢板与钢管厚度、混凝土强度和钢材强度等参数对墙体整体稳定性能的影响。通过有限元分析,得到极限稳定承载力、荷载-位移曲线和与组合剪力墙发生失稳时的应力云图。采用三项式和《钢结构设计标准》(GB 50017—2017)的整体稳定系数公式进行分段拟合,拟合出整体稳定系数计算公式。最后提出轴压作用下的组合剪力墙的极限稳定承载力公式。结果表明:拟合公式计算的整体稳定系数略低于有限元模拟结果,说明本文提出的整体稳定系数计算公式较为安全合理。

变截面工形柱平面内稳定极限承载力研究

基于非线性板壳有限元结构分析方法,对门式刚架变截面工形柱平面内稳定极限承载力进行了大挠度弹塑性分析研究。在考虑壁板局部屈曲和构件整体屈曲相关作用的同时,对影响稳定承载力的几何参数包括腹板宽厚比、翼缘宽厚比、构件楔率和构件长细比等进行了系统的分析和研究,并与现行《门式刚架轻型房屋钢结构技术规程》进行了比较,获得的结论对工程设计具有参考价值。

水库淤积物密实变化对冲淤计算与库容影响的研究

多泥沙河流水库淤积物为中细颗粒(粒径d<0.5 mm)泥沙时,初始淤积物的体积与干密度具有不稳定性,随着淤积厚度与淤积年限的增加,泥沙固体颗粒逐渐被压实,淤积物干密度增大,从而发生缩体现象,对断面法冲淤计算及水库库容变化具有重要影响。为此,在淤积物密实演化物理模式基础上,分析了淤积物体积缩小与湿密度和干密度变化之间的关系,导出了淤积物体积缩小的干密度计算公式,探讨了淤积物密实沉降对断面法年度冲淤计算的影响和淤积物密实沉降累积历程,结合三门峡水库实测资料确定了该库淤积物初期和极限稳定期干密度取值,进行了密实缩体实例计算与分析。研究表明:以各年度断面法测算的冲淤量为基础所得的水库多年累计冲淤量,并不能真正代表实际库容的损失;大量淤积物长历时密实过程会增大水库库容。

铝合金圆管轴心受压构件稳定系数的试验研究

针对网格结构的发展方兴未艾、极具活力 ,而铝合金圆管型截面构件在网格结构中的应用又日渐广泛的特点 ,通过对目前研究较少的细长 (长细比λ =6 9.4～ 194 .3)铝合金圆管型截面轴心受压构件稳定性的试验研究 ,得到构件的极限稳定承载力 ,应用最小二乘法原理拟合出构件的λ - φ曲线及相应的计算公式 .经与几种常见公式的计算结果对比 ,该公式的计算结果与试验结果吻合较其它公式的计算结果好 ,离散性小 ,所以构件的λ - φ曲线及相应的计算公式可以用于铝合金圆管型截面轴心受压构件的设计中 .

变截面轴压柱稳定试验研究

通过六根变截面柱子试验,并与等截面轴压柱进行比较,分析变截面轴心受压柱的稳定极限荷载及受力性能,给出荷载—位移曲线.

CFRP加固偏压H型钢柱承载力数值模拟分析

文章设计了6根H型钢柱构件,以CFRP粘贴层数、偏心距为参数,对H型钢柱进行了有限元数值模拟分析。通过建立"实体-壳"模型进行模拟,简述了模型单元的选取、边界条件的设定等,最终计算得出了构件的极限稳定承载力、荷载-位移曲线等重要数据,通过对比分析,得到了参数对极限稳定承载力的影响。

非对称荷载作用下具有初始几何缺陷的单层球面网壳的稳定极限承载力研究

为了研究非对称(半跨均匀)荷载对具有初始几何缺陷(节点偏差)的单层球面网壳稳定性的影响,采用N阶特征缺陷模态法模拟节点偏差,利用有限元软件ANSYS对矢跨比分别为1/3、1/4、1/5、1/6和1/7的K8型单层球面网壳进行了荷载-位移非线性全过程分析。通过对网壳结构施加全跨缺陷、半跨缺陷、全跨荷载、半跨荷载不同组合作用的方法,可以判断结构对非对称荷载的敏感程度以及非对称荷载与初始几何缺陷对结构相互影响的关系。分析表明:单层球面网壳在施加半跨缺陷和半跨荷载组合下的最不利缺陷模式均出现在前3阶,此状态下网壳的稳定极限承载力极低;矢跨比为1/5的K8型单层球面网壳结构受半跨缺陷影响较大,其稳定极限承载力下降最为显著;单层球面网壳结构全跨缺陷的最不利分布模式受荷载布置方式的影响较小;在非对称荷载作用下,初始几何缺陷的分布模式对单层球面网壳结构的稳定极限承载力影响较小。

Flexural behavior of steel reinforced engineered cementitious composite beams

In order to enhance the durability of steel encased concrete beams, a new type of steel reinforced engineered cementitious composite(SRECC) beam composed of steel shapes, steel bars and ECC is proposed. The theoretical analyses of the SRECC beam including crack propagation and stress-strain distributions along the depth of the composite beam in different loading stages are conducted. A theoretical model and simplified design method are proposed to calculate the load carrying capacity. Based on the proposed theoretical model, the relationship between the moment and corresponding curvature is derived. The theoretical results are verified with the finite element analysis. Finally, an extensive parametric study is performed to study the effect of the matrix type, steel shape ratio, reinforced bar ratio, ECC compressive strength and ECC tensile ductility on the mechanical behavior of SRECC beams. The results show that substitution concrete with ECC can effectively improve the bearing capacity and ductility of composite beams. The steel shape and longitudinal reinforcement can enhance the loading carrying capacity, while the ductility decreases with the increase of steel shape ratio. ECC compressive strength has significant effects on both load carrying capacity and ductility, and changing the ultimate strain of ECC results in a very limited variation in the mechanical behavior of SRECC beams.

楔形轴心受压柱试验研究

通过6根柱子试验,分析了楔率对楔形轴心受压柱的稳定极限荷载及受力性能的影响。

Mechanical Behavior of Rectangular Steel-Reinforced ECC/Concrete Composite Column under Eccentric Compression

In order to improve the seismic performance, deformation ability and ultimate load-carrying capacity of columns with rectangular cross section, engineered cementitious composite （ECC） is introduced to partially substitute concrete in the edge zone of reinforced concrete columns and form reinforced ECC/concrete composite columns. Firstly, based on the assumption of plane remaining plane and the simplified constitutive models, the calculation method of the load-carrying capacity of reinforced ECC/concrete columns is proposed. The stress and strain distribu- tions and crack propagation of the composite columns in different states of eccentric compressive loading are ana- lyzed. Then, nonlinear finite element analysis is conducted to study the mechanical performance of reinforced ECC/concrete composite columns with rectangular cross section. It is found that the simulation results are in good agreement with the theoretical results, indicating that the proposed method for calculating the load-carrying capacity of concrete/ECC composite columns is valid. Finally, based on the proposed method, the effects of ECC thickness, com- pressive strength of concrete and longitudinal reinforcement ratio on the mechanical performance of reinforced ECC/ concrete composite columns are analyzed. Calculation results indicate that increasing the thickness of ECC layer or longitudinal reinforcement ratio can effectively increase the ultimate load-carrying capacity of the composite column with both small and large eccentricity, but increasing the strength of concrete can only increase the ultimate Ioad- carrying capacity of the composite column with small eccentricity.

开口加劲板件的稳定极限承载力研究

为研究斜拉桥钢箱开口加劲板件的初始变形和残余应力等初始缺陷对加劲板件的稳定极限承载能力的影响,结合加劲板件材料本构关系,对不同相对宽厚比系数的开口加劲板件进行了稳定极限承载力的分析,研究了初始变形和残余应力对开口加劲板件稳定承载力的影响,研究结果表明:当相对宽厚比系数R=1时,开口加劲板件的设计对缺陷最为敏感;其整体初始变形幅值从0到L/500变化时,加劲板件的稳定极限承载力的最大差值达24.5%;其残余应力幅值σrc由0变至σY时,加劲板件的稳定极限承载力的变化最大差值达14.3%。

带杆件弯曲的网壳结构稳定极限承载分析

网壳结构稳定极限承载性能是结构分析的关键问题之一。文章基于对某网壳结构的实际检测,利用有限元分析软件ANSYS,对存在弯曲杆件的网壳结构进行几何、材料双重非线性分析,研究杆件弯曲对网壳结构稳定极限承载力的影响。结果表明:网壳结构的最终破坏源于弯曲杆件的率先失稳,部分杆件失稳后导致结构内力发生重分布,结构不会突然丧失整体承载力而是继续承载;网壳结构考虑杆件弯曲缺陷与整体缺陷较仅考虑整体缺陷时的承载力下降了28.4%,杆件弯曲缺陷对网壳结构稳定极限承载力的影响较大。

Simplified Algorithm for Out-of-Plane Critical Loads of CFST Solid-Rib Arch

The simplified algorithm for out-of-plane ultimate loadcarrying capacity of concrete-filled steel tubular( CFST) solid-rib arches under uniform vertical load was studied. The experimentally validated finite element model was developed. The out-of-plane equivalent length coefficients of solid-rib arches were obtained using out-of-plane elastic eigenvalue buckling analysis. Then the out-ofplane elastic stability coefficient was plotted against the normalized slenderness ratio,and the out-of-plane eigenvalue buckling load or elastic buckling capability of arches was calculated. Lastly effects of different parameters on the out-of-plane ultimate load-carrying capacity of CFST solid-rib arches were determined using geometric and material nonlinear finite element analysis, and a simplified algorithm was established by fitting the out-of-plane elastic-plastic stability coefficient and normalized slenderness ratio using PerryRobertson formula. Ratio of the elastic stability coefficient to the elastic-plastic counterpart was plotted against the out-of-plane normalized slenderness ratio,from which the out-of-plane elasticplastic ultimate load-carrying capacity was determined according to the corresponding elastic buckling load. Results show that the proposed simplified algorithm can accurately predict the out-of-plane eigenvalue buckling load and the elastic-plastic ultimate loadcarrying capacity of the CFST solid-rib arches.

Study on the Structural Performance of Steel Plate Shear Wall with Slits on Both Sides

This paper presents a new type of two sides slotted steel plate shear wall, and carries on the analysis to the finite element elastic buckling, respectively discusses the critical buckling load and the buckling mode. For the steel plate shear wall without stiffening ribs on both sides, the paper given the buckling coefficient formula, and give design proposal and reference value of steel plate shear wall with stiffened on both sides.

空间异形桥塔的稳定极限承载力计算方法

空间异形桥塔几何构形复杂,存在非规则截面和非理想边界特征,利用现有方法难以获得其稳定极限承载力,无法准确感知结构安全性,保守设计思维引发材料浪费。而这类桥塔形式发展快、规模大,朝着结构高耸化、材料高强化、构件薄壁化的趋势发展,稳定问题突出,需重点关注其稳定极限承载力。本研究剖析了桥塔稳定问题的实质,从非线性稳定安全系数入手,系统考虑构件长细比、双重非线性、初始缺陷的影响,寻求稳定安全系数与稳定折减系数的内在映射关系,提出了空间异形桥塔稳定极限承载力计算方法。采用矩形和圆形钢筋混凝土、纯钢箱、钢箱混凝土等典型理想压杆算例,将稳定承载力结果与规范值比对,验证了所提计算方法的可行性和准确性。最后,以一座典型的空间异形桥塔斜拉桥为工程依托,构建了精细化非线性有限元模拟策略,获得其稳定极限承载力。结果表明:该工程的弹性稳定安全系数为18.56,非线性稳定安全系数为4.125,稳定折减系数为0.899,考虑双重非线性和初始缺陷后,非线性稳定安全系数仅为弹性稳定安全系数的0.22,稳定极限承载力大幅降低。对于长细比较大的异形压杆索塔结构,设计上应充分考虑非线性对结构稳定承载力的影响。