钢管混凝土和套管混凝土短柱的抗剪强度和性能分析

TRC和TSRC短柱都是钢管混凝土柱的特殊形式。在这两种短柱中,钢管并不会跨越梁柱连接,并且长度也短于混凝土核心筒。在地震区,短柱容易产生脆性剪切破坏。TRC和TSRC短柱广泛应用于桥梁、高层建筑和大型厂房,所以对短柱的剪切破坏及如何提高此类柱的延性便显得非常重要。研究目的是为TRC和TSRC短柱的计算开发一个非线性有限元模型,并将计算结果与试验结果进行对比。基于有限元计算结果,采用弹塑性方法来分析钢管的应力状态,并利用一个改进的ACI设计方法去计算TRC和TSRC短柱的名义抗剪强度。     

高强混凝土短柱的抗剪强度

通过对轴向荷载和水平低周反复荷载作用下高强混凝土框架短柱的试验研究,得出了高强混凝土框架短柱抗剪强度的计算公式,计算结果与试验值较为吻合。     

循环荷载作用下型钢高强高性能混凝土短柱抗剪承载力研究

基于循环荷载作用下的型钢高强高性能混凝土短柱的试验结果,对影响型钢高强高性能混凝土柱剪切破坏的剪跨比、轴压比、混凝土强度、含钢率以及配箍率等主要因素进行分析。通过单独考虑钢筋混凝土部分、型钢部分、轴压力部分对柱抗剪承载力的贡献,根据叠加原理,并考虑位移延性需求的影响,分别给出型钢高强高性能混凝土短柱剪切黏结破坏以及剪切斜压破坏两种情况下的抗剪承载力计算公式。通过与试验结果的对比发现,所建立的公式能较好地反映型钢高强高性能混凝土短柱的抗剪承载力,研究结果可为型钢组合结构规范的修订以及工程设计提供理论依据和参考。     

型钢再生混凝土短柱抗剪承载力计算

为研究型钢再生混凝土短柱的抗震性能,对8个型钢再生混凝土短柱试件,采用悬臂柱式加载装置进行低周反复荷载试验,观察其受力过程和破坏形态。试验表明,剪跨比为1.4的型钢再生混凝土短柱以剪切斜压破坏形态为主;分别研究了轴压比、配箍率和再生粗骨料取代率对试件抗剪承载力的影响;分析了型钢再生混凝土短柱的受力特点和破坏机理;推导出型钢再生混凝土短柱发生剪切斜压破坏时的抗剪承载力计算公式。最后,为便于工程应用,在试验与理论分析的基础上,提出了型钢再生混凝土短柱抗剪承载力简化计算公式,计算结果与试验结果符合较好。     

钢管混凝土柱抗剪承载力公式

本文以40个铜管混凝土柱抗剪力学性能的试验结果为依托,并结合相关研究,对钢管混凝土柱抗剪承栽力的影响因素进行了分析,以试验结果对现有的抗剪承载力计算公式进行比较,并推荐了工程设计的实用计算公式。     

钢管混凝土柱抗震性能比较

对往复荷载作用下钢管混凝土柱进行有限元模拟,并与试验结果做比较。结果表明,计算值和试验值吻合较好。在此基础上,分别模拟计算同等条件下钢管混凝土柱和钢筋混凝土柱,分析对比钢管混凝土柱和钢筋混凝土柱的承载力、延性、耗能和刚度退化等力学性能。研究表明:同等条件下,钢管混凝土柱的最大承载力为钢筋混凝土柱的1.55倍,延性系数为1.53倍。钢管混凝土柱耗能指标均大于钢筋混凝土柱,表明钢管混凝土柱比钢筋混凝土柱具有更好的抗震性能。     

矩形钢管混凝土柱抗剪性能研究

对矩形钢管混凝土柱抗剪性能的研究现状、目前取得的研究成果和存在的问题进行了介绍与探讨,并为其进一步的研究提出了一些建议,以完善我国相关的规范建设,推动钢管混凝土结构的进一步发展。     

钢管混凝土短柱的强度计算

本文利用极限平衡法 ,通过线性拟合σ r fc 与的关系 ,从理论上推导了薄壁短柱的极限强度计算公式。所得公式形式简单 ,便于在实际中应用。经用文献中的试验数据对公式计算结果进行对比 ,两者吻合良好。     

Seismic behavior and shear strength of tubed RC short columns

Reinforced concrete (RC) short columns are vulnerable to brittle shear failure during an earthquake. The objective of this research is to evaluate the performance enhancement of RC short columns tubed with circular or square tubes. Eight short columns were tested under combined constant axial load and cyclic lateral load. The tested specimens included three circular tubed RC (CTRC) columns and three square tubed RC (STRC) columns. Two common RC short columns including one circular RC column and one square RC column were also tested as control specimens. The test results indicated that common RC short columns suffered brittle shear failure with little ductility, while the ductility of tubed RC short columns was excellent due to the effective confinement of the outer thin tube to the core concrete. The lateral load strength of CTRC short columns increases with the increasing of axial load ratio, while the axial load ratio has little effect on the plastic deformation capacity of CTRC short columns. The shear strength increases with increasing of axial load ratio, while the plastic deformation capacity decreases with increasing of axial load ratio for STRC short columns. A circular tube prevents the core concrete from shear failure more effectively than a square tube for the tubed RC short columns. A modified ACI design method is adopted to calculate the nominal shear strength of STRC columns as well as CTRC columns based on the test and analysis results.     

轴力作用下钢管短柱的性能和强度分析

对轴力作用下钢管短柱的性能和强度进行了试验和数值分析。对包括20个圆形和方形钢管混凝土短柱在内的40个构件进行了试验,以分析其在轴压作用下的破坏模式和轴向承载强度。同时也对管的径(宽)厚比和混凝土的抗压强度的影响进行了分析。对钢管混凝土柱中管的高径(宽)比的影响进行分析,以探究钢管和混凝土之间的粘结和摩擦对钢管混凝土柱性能的影响。利用钢管的弹塑性分析研究轴压下短柱的受力机制。提出了公式用以预测钢管混凝土短柱的极限轴向承载强度,并将预测结果与试验结果进行了对比。     

钢管混凝土(SRC)短柱的轴向受压性能和强度分析

给出轴压下钢管混凝土短柱性能的试验和理论研究。共对14根圆钢管混凝土短柱和15根方钢管混凝土短柱进行试验,以研究钢管混凝土短柱的失效模式和轴压性能。分析了直径(或宽度)、相对厚度比对钢管性能的影响。试验结果表明:在相同配钢率的前提下,钢管混凝土短柱比普通混凝土短柱的受压承载力大。钢管的弹塑性分析可用于研究轴压下钢管混凝土短柱的破坏机理。基于已有的试验成果,提出求解钢管混凝土短柱的轴向受压强度的方程式。     

方钢管钢筋混凝土短柱与方钢管钢骨混凝土短柱的滞回性能分析及设计

方钢管钢筋混凝土短柱与方钢管钢骨混凝土短柱(STRC与STSRC)是将纵向钢筋置于冷弯薄壁钢管中。在这项研究中,对6根STRC和STSRC短柱进行固定轴压力下和往复侧向压力下的试验研究,分析两种构件的抗震性能。主要参数为轴压比和纵筋的配筋率。建立三维非线性有限元模型,模拟试件的性能和强度。基于试验和数值模拟结果,提出计算STRC和STSRC短柱剪切强度的设计公式。     

Seismic behavior and strength of tubed steel reinforced concrete (SRC) short columns

The seismic behavior of tubed SRC short columns has been investigated by testing eight specimens subjected to combined constant axial compression and lateral cyclic load. Three circular tubed SRC columns (CTSRC) and three square tubed SRC (STSRC) columns were tested in this research with two common SRC columns for comparison. Different axial load ratios (n₀=0.3, 0.4 and 0.5) have been adopted for the constant axial load. The test results indicate that the shear strength, plastic deformation capacity, ductility index, and energy dissipating capacity of the tubed SRC short columns were much higher than those of the SRC columns with the same steel ratio and axial compressive load. The lateral load strength of CTSRC and STSRC short columns increased with an increment in axial load level, while the axial load ratio has no obvious effect on the plastic deformation capacity of CTSRC and STSRC short columns. The steel tubes prevented the shear failure of the concrete more effectively in the circular columns than in the square ones. Shear connector studs should be used in CTSRC and STSRC short columns to prevent bond failure between concrete and flanges of the steel section. A modified ACI design method was adopted to calculate the nominal shear strength of STSRC columns as well as CTSRC columns.     

CFRP加固混凝土柱受剪承载力计算方法的分析

列举了国内外有关设计标准、指南和文献中的 7种CFRP布加固钢筋混凝土柱受剪承载力的计算方法 ,对国内外 3 3根柱的试验结果进行了验算 ,分析了各建议公式计算结果的可靠性和CFRP布对受剪的贡献 ,在此基础上提出了实用计算建议 ,供编制有关设计规范和工程设计参考。     

Shear strength and behavior of tubed reinforced and steel reinforced concrete (TRC and TSRC) short columns

Tubed RC and SRC short columns are special kinds of concrete filled tubular columns but the steel tube does not pass through the beam–column connection and is shorter than concrete core. In areas that suffered earthquakes, the short columns are vulnerable to brittle shear failure. TRC and TSRC short columns are widely used in bridges, high-rise buildings and large factories. So it is important to investigate the behaviors and approaches to improve the ductility of these kind of columns. The aim of this study is to develop a nonlinear finite element model (FEM) for TRC and TSRC short columns and to compare the results with those experimentally captured. Depending on the FEM results, the elastic–plastic method was used to analyze the stress status of the steel tube. A modified ACI design method is adopted to calculate the nominal shear strength of TRC and TSRC short columns based on the FEM and analysis results.     

短牛腿抗剪强度的敏感性因素分析

利用正交试验设计法对影响钢筋混凝土短牛腿抗剪承载力的各因素进行分析,考虑的因素包括混凝土抗压强度、剪跨比和钢筋屈服强度。通过分析可知剪跨比对短牛腿抗剪强度最为敏感,混凝土抗压强度和钢筋屈服强度次之。希望本文内容可作为进一步研究钢筋混凝土短牛腿受力性能的依据。     

Behavior and strength of tubed RC stub columns under axial compression

This paper presents an experimental and analytical study on the behavior of axially compressed tubed RC stub columns. Forty specimens including twenty circular tubed RC (STRC) and twenty square tubed RC (STRC) stub columns were tested to investigate the failure mode and axial load strength of tubed RC columns subjected to axial compression. The effect of diameter/width to thickness ratio of the tubes and compressive strength of concrete were also studied. The effect of height to diameter/width ratio of the separated tube in tubed RC columns was studied to investigate the effect of bond and friction between tube and concrete on the behavior of tubed RC columns. Elastic–plastic analysis on the steel tube was employed to study the mechanism of tubed RC stub columns subjected to axial compression. Equations for the prediction of the ultimate axial load strength of tubed RC stub columns were proposed and the results from prediction were compared with the test results.