新型装配式框架干式连接节点核心区暗牛腿剪切性能分析

对预制装配式框架结构提出一种新型装配式框架连接节点,结合ABAQUS有限元分析软件对节点区整体受力性能进行了分析,利用拉压杆模型的摩擦抗剪理论对钢筋混凝土暗牛腿进行了分析,结果表明,利用新型干式企口连接节点、钢筋混凝土暗牛腿缺口梁干式节点能够满足承载力且性能优异。     

新型全预制装配框架体系中斜企口梁的受力性能分析

在新型全预制装配框架体系中,斜企口梁是重要的受力构件.为了获得斜企口梁的极限承载力,应用剪切摩擦和拉压杆模型等理论,对刚性企口连接斜企口梁在复杂受力状态下的多种破坏形式给予分析,推导出相应的极限承载力公式,并通过已有的试验数据对承载力理论计算值进行验证.结果表明,该极限承载力公式具有较高精度.     

全预制钢筋混凝土干式框架节点中暗牛腿的分析

在全预钢筋制混凝土框架梁柱干式暗牛腿节点中,钢筋混凝土暗牛腿是重要的竖向传力构件。应用拉压杆模型方法和剪力摩擦理论对暗牛腿进行分析,推导出其承载力公式,并提出相应的设计建议。然后应用有限元分析软件ANSYS对该连接中钢筋混凝土暗牛腿进行了有限元分析,并对承载力公式进行了验证。提出的设计方法可以为此类暗牛腿的设计提供相应参考。     

钢管混凝土叠合柱节点环梁受弯承载力计算方法

钢管混凝土叠合柱环梁节点是一种连接叠合柱与钢筋混凝土梁的连接节点,其环梁受弯承载力计算方法有待研究。考虑管外混凝土的轴压作用,采取极限平衡法对环梁破坏隔离体受力分析,对现有钢管混凝土柱节点环梁受弯承载力计算方法进行了修正,使其更加适用于钢管混凝土叠合柱节点环梁,计算结果与静力试验结果对比显示,后者高约28%。根据试验结果研究对公式进行修正,采用ABAQUS有限元静力模型对不同轴压比下环梁的受弯承载力公式进行了验证,对比显示有限元分析结果略高于修正后的计算值,二者吻合较好。结果表明,考虑轴压力修正后的公式可以用于钢管混凝土叠合柱节点环梁受弯承载力的计算,公式计算结果偏于保守。     

蒸压硅酸盐企口砌块砌体抗压性能研究

蒸压硅酸盐企口砌块是新型墙体材料,研究其砌体受压性能,为编制《蒸压硅酸盐企口小型砌块应用技术规程》提供理论依据。按照GB/T 50129—2011《砌体基本力学性能试验方法标准》进行抗压试验,分析蒸压硅酸盐企口砌块砌体受压破坏现象、受压承载力及变形性能,并与现行规范中混凝土多孔砖的抗压强度进行对比。结果表明,试验测得蒸压硅酸盐企口砌块的抗压强度设计值大于GB 50003—2011中混凝土多孔砖砌体的抗压强度设计值。将试验数据回归,得到蒸压硅酸盐砌体抗压平均强度建议公式、弹性模量建议公式,蒸压硅酸盐企口砌块砌体具有良好的抗压性能。     

斜次梁箍筋布置方式研究

通过有限元数值模拟,规范公式计算两种方法分别研究主次梁斜交时(次梁为斜梁)次梁箍筋布置方式对其抗剪承载力的影响,并将两者结果进行对比分析,结果表明:有限元软件可以较好地模拟钢筋混凝土梁的破坏过程,次梁箍筋采用文中两种方式布置对其抗剪承载力影响不大,均可根据钢筋混凝土结构设计规范公式计算其抗剪承载力,其结果偏于安全。     

多腔钢管钢筋混凝土短柱轴压承载力实用计算方法

多腔钢管钢筋混凝土柱具有承载力大、抗震延性好、易于施工等优点,为巨型结构提供了一种有效的解决方案,并在高银117等超高层项目中得到了应用,但是尚缺乏相应的承载力理论计算公式。首先基于Richart强度公式,对正方形2等分4腔体钢管钢筋混凝土短柱进行轴压承载力的理论推导,得到了相应的承载力公式,然后推广到正方形多等分的多腔钢管钢筋混凝土巨柱;给出了基于过-张-翁强度公式的正方形等分多腔体钢管钢筋混凝土短柱轴压承载力公式和低箍筋约束效应下的多腔钢管钢筋混凝土短柱承载力公式;结合承载力公式对腔体的设置进行了分析,对于大截面巨柱,多腔钢管钢筋混凝土巨柱较单腔钢管钢筋混凝土柱有效提高了承载力,多腔钢管钢筋混凝土巨柱腔体不宜过多。     

基于ABAQUS的混凝土结构非线性有限元分析

利用通用有限元软件ABAQUS对钢筋混凝土简支梁承载力的有限元分析过程进行模拟,并进行了混凝土结构非线性静力计算,分析结果表明,有限元软件计算结果与规范公式计算结果吻合的较好,从而证明了ABAQUS可以对混凝土结构进行准确的静力模拟。     

钢板焊接连接的带水平接缝装配式RC剪力墙抗震性能试验研究

为了研究采用钢板焊接连接的带水平接缝预制装配式钢筋混凝土剪力墙的抗震性能,设计了4个装配式钢筋混凝土剪力墙足尺试件并进行低周往复水平荷载试验,研究参数包括连接钢板厚度、侧向钢板设置和轴压比。结果表明：各试件均为压弯破坏,水平承载力在186~288kN之间,极限位移在25.74~29.37mm之间,滞回曲线为饱满的弓形,延性和耗能能力较好,刚度退化较慢;在连接钢板满足强度要求前提下,增大连接钢板厚度、增加侧向钢板对剪力墙的延性、刚度、承载能力和耗能能力影响较小;提高轴压比可以明显提高装配式剪力墙的刚度和承载能力,但会降低其耗能能力。采用ABAQUS有限元软件对装配式剪力墙抗震性能进行分析,所建立的有限元模型可以较好地模拟装配式剪力墙的受力性能。通过对比采用规范公式计算的承载力与试验承载力,表明可以采用JGJ 3—2010《高层建筑混凝土结构技术规程》中的公式计算文中装配式剪力墙的承载力,并给出了连接钢板的计算方法。     

内嵌CFRP板条加固RC梁抗剪承载力分析

分别对未加固和内嵌CFRP加固的钢筋混凝土梁建立了有限元模型,应用ANSYS软件进行非线性有限元分析,研究梁挠度和承载力,并与试验结果进行了比较,分析比较模拟结果和试验结果表明,所采用的有限元模型的合理性和有限元分析方法的正确性及CFRP加固钢筋混凝土梁可以显著提高其抗剪承载力。     

混凝土悬臂深梁设计方法的试验研究及其在上海博物馆工程中的应用

本文绘出14片悬臂深梁在一次加载和反复加载下的试验结果。讨论破坏形态，分析受力性能，提出承载力计算公式，计算值与试验值符合良好。在试验基础上提出悬臂深梁设计方法，并应用于上海博物馆工程16片悬臂深梁设计。根据模拟关系近似估计实际的悬臂深梁的承载能力及大体的安全储备，对设计提出改进意见，供工程应用及修订规范参考。     

钢-混凝土连续组合梁的稳定

连续组合梁的局部失稳和侧向失稳是影响承载能力的重要因素 ,我国现行设计规范对组合梁的稳定计算主要沿用钢结构梁的设计方法 ,与组合梁实际失隐情况不符。为此 ,评述了近年来连续组合梁失稳方面的研究进展 ,介绍了英国和欧洲规范以及AASHTO等有关稳定设计方法 ,可供工程设计人员参考     

剪力墙下部地基梁的有限元分析

采用有限元分析程序ANSYS,对剪力墙下部地基梁的三种截面和配筋各异的情况,建立了包括剪力墙、桩和地基梁的整体模型。通过分析和比较,指出目前的有些设计思路使得该类地基梁的设计截面和配筋明显偏大。应该采用有限元非线性静力分析的手段进行该类地基梁的设计,以得到安全经济的结果。     

北京凤凰苑工程转换梁结构设计

北京凤凰苑公建区工程由两栋酒店和一栋写字楼组成,其中两栋酒店地上部分采用部分框支-剪力墙结构,存在着多种类型的转换梁,如托柱转换梁、上部墙体开有边门洞的托墙转换梁、框支主次梁二次转换结构等。结合该工程的设计过程,给出了较有特色的转换梁设计结果。介绍了较为复杂的框支主次梁二次转换结构的计算法。     

Experimental and numerical investigation on LTB strengths of monosymmetric compact I-beams with thickness-stepped-flanges

This paper investigates the inelastic lateral torsional buckling, LTB, of doubly stepped singly symmetric compact I-beams under two concentrated loads. The results are obtained by conducting actual destructive tests on the beams using a testing machine and running simulation tests using the finite element program, ABAQUS. The main factors that are considered for the analyses are the degree of symmetry, the loading and supports, the stepped beam factors and the length. For this study, the beams have simple supports. The monosymmetric ratio of all the beams analyzed is fixed at 0.7. The unbraced lengths of the beams are 3 meters and 4 meters. The results obtained from ABAQUS are compared with the results from design specifications to determine the effects of steps and from proposed design equations to determine the equations’ applicability and safety. The results revealed that the stepped beams did have an increase in capacity in comparison with the prismatic beams and that the proposed equations are suitable to be used in predicting the strength of stepped beams under the observed loading condition.     

Optimum design of cellular beams using harmony search and particle swarm optimizers

Cellular beams became increasingly popular as an efficient structural form since their introduction. Their sophisticated design and profiling process provide greater flexibility in beam proportioning for strength, depth, size and location of circular holes. The main goal of manufacturing these beams is to increase the moment of inertia and section modulus, which results in greater strength and rigidity. Cellular beams are used as primary or secondary floor beams in order to achieve long spans and service integration. In this study, the design problem of cellular beams is formulated as optimum design problem. The minimum weight is taken as the design objective while the design constraints are implemented from The Steel Construction Institute Publication Number 100. The design methods adopted in this publication are consistent with BS5950 parts 1 and 3. The formulation of the design problem considering the limitations of the above mentioned turns out to be a discrete programming problem. Harmony search and particle swarm optimization methods are used for obtaining the solution of the design problem. The design algorithms based on these two techniques select the optimum UB section to be used in the production of a cellular beam subjected to a general loading, the optimum hole diameter and the optimum number of holes in the cellular beam. Furthermore, this selection is also carried out such that the design limitations are satisfied and the weight of the cellular beam is the minimum. A number of design examples are considered to demonstrate the efficiency of the algorithm presented.     

Lateral buckling strengths of cold-formed rectangular hollow sections

Code rules for designing steel beams against lateral buckling which are based on data for hot-rolled I-sections are unnecessarily conservative when used for cold formed rectangular hollow section beams.Cold-formed rectangular hollow section beams have different stress-strain curves, residual stresses, and crookedness and twist. The effects of residual stress on the inelastic buckling of I-section beams are not nearly as pronounced for hollow sections with two webs, while the strengthening effects of pre-buckling deflections are greater for hollow sections. Simplistic code rules for top flange loading are very conservative when applied to hollow sections.This paper reviews elastic lateral buckling behaviour and the strength rules used to design steel beams. It develops realistic models for cold-formed rectangular hollow beams which are analysed to predict the effects of moment distribution, load height and yield stress on their strengths. The results of the analyses are used to develop improved design rules which remove much of the conservatism of present design rules.     

偏心支撑钢框架的设计

简述了偏心支撑钢框架结构的工作原理及特点,介绍了偏心支撑钢框架的设计计算方法,其中重点介绍了各杆件的内力计算：耗能梁段设计、非耗能梁段设计、支撑设计和框架柱设计,为工程设计人员提供了指导。     

高层建筑钢筋混凝土连梁的设计和研究

提高钢筋混凝土连梁的位移延性和耗能能力是保证高层建筑结构达到其抗震设防目标的关键,本文作者对改善钢筋混凝土连梁延性的设计方法和研究现状进行了分析.     

Steel cantilever strength by inelastic lateral buckling

Methods used for the design of steel beams supported at both ends are not well suited for the design of cantilevers against lateral buckling. The end restraints are very different for cantilevers, and the maximum displacements and twist rotations take place at the free ends, instead of near mid-span. Consequently, their buckling modes are very different to those of supported beams. The methods of allowing for the effects of the moment distribution on the elastic and inelastic buckling of supported beams use a mean of the moment distribution, which is weighted to allow for the maximum deformations being near mid-span. These methods are clearly inappropriate for cantilevers whose deformations are greatest at the free ends.Lateral buckling design methods for cantilevers are modifications of the methods for supported beams, but are of doubtful accuracy, and may be over conservative. In some cases there is little or no design guidance.This paper summarizes information on the effects of the moment distribution and load height on the elastic buckling of cantilevers which can be used in the method of design by buckling analysis. It then extends a method of designing supported beams by inelastic buckling analysis to allow for the effects of the moment distribution on the inelastic buckling of cantilevers. This extended method is then used to provide improved design methods for cantilevers which are consistent with those for simply supported beams. A worked example is summarized.