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1.
采用带约束拉杆矩形钢管混凝土的本构关系,利用纤维模型法对带约束拉杆矩形钢管混凝土短柱承载力进行了数值分析,计算结果与试验结果吻合良好。利用经试验结果验证的计算程序对带约束拉杆矩形钢管混凝土短柱轴压和单、双向偏压承载力进行了较系统的参数分析,回归出带约束拉杆矩形钢管混凝土轴压和单、双偏压承载力简化计算公式,公式的计算精度高,形式简单,便于应用,可供工程设计参考。  相似文献   

2.
何振强  蔡健 《工业建筑》2008,38(3):12-15
在现有一般方形钢管混凝土轴压短柱承载力的主要计算方法的基础上,利用前期对在带约束拉杆方形钢管混凝土的本构关系的研究基础上推导出的带约束拉杆方形钢管混凝土轴压短柱的承载力计算公式,结合实际工程应用的需要进行简化。分别应用该公式、EC4(1996)规范及我国军用标准GJB(2000)的相关公式对带约束拉杆和不带约束拉杆的方形钢管混凝土轴压短柱试件极限承载力进行计算。计算值与试验值对比表明:对一般方形钢管混凝土轴压短柱试件,三者计算结果比较接近,均能较好反映试件的真实承载力;对设置了约束拉杆的试件,该公式由于考虑了拉杆的约束作用,给出的计算结果更为合理,EC4(1996)及GJB(2000)给出结果的均值与试验值接近,但离散性偏大。  相似文献   

3.
介绍15个带约束拉杆方形钢管混凝土短柱和8个带约束拉杆矩形钢管混凝土短柱的轴压试验结果,分析钢管壁厚度、拉杆直径、拉杆水平间距等参数对其轴压性能的影响。试验研究结果表明,约束拉杆的设置有助于延迟钢管的局部屈曲、提高方形钢管混凝土短柱的轴压承载力和延性,提高矩形钢管混凝土短柱的延性。约束拉杆的作用主要表现为对核心混凝土的约束作用及通过改变钢管侧壁局部屈曲的边界条件从而提高钢管的屈曲强度。同时,在合理考虑拉杆作用的基础上,应用等效侧向压力的概念和基于混凝土真三轴试验的破坏准则确定核心混凝土的峰值强度,提出带约束拉杆方形、矩形钢管混凝土短柱轴压承载力的计算方法,承载力计算结果与试验结果吻合良好。  相似文献   

4.
带约束拉杆矩形钢管混凝土短柱轴压性能的试验   总被引:4,自引:0,他引:4  
蔡健  何振强  陈星 《工业建筑》2007,37(3):75-80
针对约束拉杆对矩形钢管混凝土柱轴压力学性能的影响,对8个轴压试件进行试验,其中1个不设约束拉杆,7个设置约束拉杆。试验主要参数为约束拉杆直径和间距,钢管宽厚比,截面长宽比。试验结果表明:相对于方形截面试件,矩形截面试件设置约束拉杆后,在轴向压力作用下,试件的承载力提高幅度不明显,但对应于峰值荷载的竖向应变值随约束拉杆的加强相应增大,试件的塑性变形能力增大,延性提高。利用国内已有文献中关于矩形钢管混凝土承载力计算方法及EC4(1996)关于方形钢管混凝土计算方法,对带约束拉杆矩形钢管混凝土轴压试件承载力进行计算,发现计算结果比试验值偏低,计算方法偏于保守。  相似文献   

5.
孙刚  蔡健 《建筑技术》2010,41(1):31-33
在试验的基础上,分析了带约束拉杆L形钢管混凝土短柱的受力机理,将带约束拉杆L形钢管混凝土短柱划分成一个方形和两个带约束拉杆的矩形钢管混凝土短柱,提出了轴压下带约束拉杆L形钢管混凝土短柱的承载力计算公式,并结合试验数据确定了计算公式中的参数。用建议计算公式对有关试件进行计算,计算结果与试验结果吻合良好。  相似文献   

6.
矩形钢管混凝土短柱轴压承载力   总被引:1,自引:0,他引:1  
提出一种矩形钢管混凝土短柱轴压承载力计算的新方法。与已有的计算方法不同之处在于,所提出的方法考虑了矩形钢管截面长边、短边对核心混凝土约束作用大小不同的特点,应用基于混凝土真三轴受力试验的破坏准则确定管内核心混凝土的峰值强度;同时,考虑矩形钢管截面长边、短边的竖向强度的差异,分别计算矩形钢管长、短边的竖向强度。应用新方法对56根矩形钢管混凝土柱试件的轴压承载力进行计算,计算结果与试验结果比较表明,两者吻合良好。  相似文献   

7.
矩形钢管混凝土轴压短柱承载力计算   总被引:10,自引:0,他引:10  
在实验的基础上 ,本文对文献 [1 ]中方形钢管混凝土短柱轴心受压公式进行了修正 ,考虑了矩形截面长宽比的影响 ,提出了矩形钢管混凝土短柱的承载力计算公式。  相似文献   

8.
带约束拉杆矩形钢管混凝土短柱偏压性能的试验研究   总被引:3,自引:0,他引:3  
对7个带约束拉杆和2个不设约束拉杆矩形钢管混凝土短柱进行偏心受压试验研究,主要研究偏心率、约束拉杆水平间距对矩形钢管混凝土短柱偏压性能的影响。试验研究结果表明,在偏心压力作用下,约束拉杆的设置有助于提高矩形钢管混凝土短柱的延性,延迟钢管的局部屈曲。带约束拉杆矩形钢管混凝土柱的偏压承载力随偏心率的增大而减小。在相同偏心率下,试件延性随拉杆水平间距减小而增大。  相似文献   

9.
为研究带拉杆约束矩形截面钢管混凝土短柱的抗震性能,以轴压比、约束拉杆间距和截面长宽比为主要参数,进行了4个无拉杆约束和11个带拉杆约束矩形钢管混凝土短柱试件的低周往复加载试验。研究了其破坏过程、滞回性能、承载能力、变形能力、刚度退化及耗能能力等,并基于数值分析给出了带约束拉杆矩形截面钢管混凝土短柱压弯承载力计算式。结果表明:钢管板件宽厚比为50和67、剪跨比为3的矩形截面钢管混凝土短柱的滞回曲线饱满,没有明显的捏缩;设置约束拉杆提高了试件的承载能力、变形能力及耗能能力;带约束拉杆试件的极限位移角在1/19~1/50之间,位移延性系数在3.28~6.25之间;破坏时的等效黏滞阻尼系数在0.3以上;增加轴压比降低了试件的延性;减小约束拉杆间距可明显改善柱的抗震性能;保持截面宽度不变,增加截面长宽比,可提高试件承载力,但延性降低。提出的带约束拉杆矩形截面钢管混凝土短柱的压弯承载简化计算式的计算结果与试验结果吻合较好。  相似文献   

10.
本文介绍了带约束拉杆矩形钢管混凝土柱的试验,分析、解释了试验现象,对试件的破坏过程、荷载-应变关系、约束拉杆的作用等方面作了较为详细的讨论。  相似文献   

11.
带约束拉杆T形钢管混凝土短柱轴压性能的试验研究   总被引:7,自引:0,他引:7  
介绍11个带约束拉杆和5个不带约束拉杆的T形钢管混凝土轴压短柱试件的试验研究,讨论在不同约束拉杆间距与直径、钢板厚度与屈服强度、截面尺寸下带约束拉杆T形钢管混凝土短柱的破坏特点、承载力、拉杆与钢管的应变特点等轴压性能。结果表明:约束拉杆的设置改变了钢管的屈曲模态,延迟钢管局部屈曲的发生,有助于T形钢管混凝土轴压短柱的承载力和延性的提高。采用现有规范或规程的计算公式对试件轴压承载力进行计算,对不同计算方法的适用性进行探讨。  相似文献   

12.
This paper is concerned with the eccentric load behavior of L-shaped concrete-filled steel tubular (CFT) stub columns with binding bars. Eight specimens with binding bars and one without binding bars were tested to examine the effects of horizontal spacing and diameter of binding bars, load eccentricity ratio, and load angle on the failure modes, bearing capacity and ductility of L-shaped CFT stub columns. Experimental results demonstrate that the local buckling of the steel tube can be postponed by setting binding bars, and the bearing capacity and curvature ductility of the L-shaped CFT stub columns are at most 1.04 and 3.31 times those without binding bars, respectively, and the plane section assumption can also be satisfied. Based on a modified stress–strain relationship of confined concrete, the fiber element analysis is applied to predict the bearing capacity of the specimens, and the predicted results agree well with the experimental ones. Then the parametric studies using the proposed theoretical model are carried out to further study the fundamental behavior of eccentrically loaded L-shaped CFT stub columns with various steel yield strengths, sectional steel ratios, cube strengths of concrete, confinement coefficients of binding bars, sectional aspect ratios and load angles. Finally, simplified interaction formulas are put forward to predict the Mx/Mx–My/My′ curves for the L-shaped CFT stub columns with or without binding bars subjected to biaxial eccentric load, and the theoretical results predicted by the simplified formulas agree well with those predicted by the fiber element analysis program.  相似文献   

13.
In this paper, a total of 250 experimental tests of axially loaded circular concrete-filled steel tube (CFT) stub columns, published in the literature was summarized. The applicability of the current design codes such as ACI, Australian Standards, AISC, AIJ, Eurocode 4, DL/T and some available empirical models proposed by various researchers for calculating the axial capacity of circular CFT stub columns was examined using these experimental data. Based on the investigations, four new empirical models for predicting the axial capacity of circular CFT stub columns are proposed. The comparisons between the experimental results and the predictions of these models show that the proposed empirical models provide a direct, compact, and efficient representation of the ultimate strength of circular CFT stub columns made with not only normal strength but also high strength steel tubes and concrete. Finally, the limiting values of the maximum effective length, the compressive strength of concrete, the yield strength of steel tubes and the diameter-to-thickness for circular CFT stub columns with respect to the present empirical models are suggested. It is expected that engineers can easily use the present empirical models to estimate the axial capacities of circular CFT stub columns for engineering designs.  相似文献   

14.
带约束拉杆T形钢管混凝土短柱偏压试验研究   总被引:4,自引:0,他引:4  
进行了16根带约束拉杆和11根不带约束拉杆T形钢管混凝土短柱试件的偏压试验研究,分析了不同荷载角、偏心率、约束拉杆间距下该类型柱的偏压性能。试验结果表明:约束拉杆的设置减小钢板的屈曲半波长、延迟钢管局部屈曲的发生、提高核心混凝土的约束作用,有助于提高该类型柱的承载力和延性;临近或达到极限荷载时近力侧拉杆及钢板对核心混凝...  相似文献   

15.
This paper presents a theoretical study on the elastic local buckling of steel plates in rectangular concrete-filled steel tubular (CFT) columns with binding bars under axial compression. It is assumed that the unloaded edges of the steel plate are elastically restrained against rotation, whereas the loaded edges are clamped. Based on the energy method, the formulas for elastic local buckling strength of the steel plate in rectangular CFT columns under axial compression are derived, which are calibrated with the experimental results. Then the formulas are employed to study the elastic local buckling of steel plates in rectangular CFT columns with binding bars under axial compression. It is shown that the binding bars can increase the local buckling coefficient, which results in improvement of the capacity of the steel plate to resist local buckling. Finally, appropriate spacing of binding bars, appropriate limitation for aspect ratio and corresponding appropriate limitation for width-thickness ratio are suggested for rectangular CFT columns with binding bars under axial compression.  相似文献   

16.
In order to improve the co-working performance between the core concrete and steel tube for large-section rectangular concrete-filled steel tubular (LSCFT) columns when a vertical load is directly applied to the steel tube, a distributive beam is proposed as a load transferring measure. Four scaled LSCFT column specimens with different details were tested under axial compression to investigate the mechanical behavior and load transferring mechanism of the LSCFT columns with a distributive beam. The experimental results indicated that the bearing capacity of the LSCFT columns without a distributive beam was close to the yield capacity of the steel tube and the load shared by the core concrete was negligible. In contrast, the specimen with a distributive beam and inner stiffeners could bear a much higher load. In addition, refined nonlinear finite element models were developed to further analyze the load-transferring mechanism of LSCFT columns with different details. The numerical results showed that the ultimate load of the specimen with a distributive beam and inner stiffeners was much closer to the theoretical value calculated from Chinese code CECS159:2004. Setting a distributive beam and inner stiffeners simultaneously in LSCFT columns could ensure the cooperation between the core concrete and steel tube.  相似文献   

17.
轴压下带约束拉杆L形钢管混凝土短柱的试验研究   总被引:10,自引:0,他引:10  
对7根轴压下L形钢管混凝土短柱(6根带约束拉杆,1根无约束拉杆)进行试验,介绍试件和试验方案的设计,分析钢板厚度、约束拉杆的直径和水平间距等主要参数对带约束拉杆L形钢管混凝土短柱极限承载力和延性的影响.试验表明,在L形钢管混凝土短柱上设置约束拉杆,可以有效地延缓钢管壁的局部屈曲,改善钢板对核心混凝土的约束效应,提高该类构件的极限承载力和延性.最后,将带约束拉杆L形钢管混凝土短柱划分成1个方形和2个带约束拉杆的矩形钢管混凝土短柱,并借鉴带约束拉杆方形钢管混凝土承载力的计算公式,对带约束拉杆L形钢管混凝土短柱的极限承载力计算方法作初步探讨.  相似文献   

18.
Axial load behavior of square CFT stub column with binding bars   总被引:3,自引:0,他引:3  
This paper is concerned with the axial load behavior of square concrete filled steel tubular (S-CFT) stub columns with binding bars provided to improve the mechanical behavior of S-CFT columns. Ten specimens with binding bars and 5 specimens without binding bars were tested to examine the effects of width-to-thickness ratios and binding bars on ultimate strength, stiffness and ductility of S-CFT columns. A method for calculating ultimate strength is proposed based on a constitutive model of confined concrete and a simplification corresponding to this method is conducted. Finally, the method proposed in this paper is verified with experimental results in this test program and data from other experiments. Corresponding values of ultimate strength calculated by EC4(1996) and GJB(2000) are given respectively for comparison. For S-CFT stub columns with binding bars, the results predicted by the method proposed herein agree well with the experimental results while that predicted by the methods of EC4(1996) and GJB(2000) scatter from the experimental results; for S-CFT without binding bars, the results given by the three methods mentioned above are all reasonable.  相似文献   

19.
带约束拉杆方形钢管混凝土柱偏压性能   总被引:1,自引:1,他引:1       下载免费PDF全文
介绍了14个带约束拉杆方形钢管混凝土单向偏压柱试件的试验研究结果,研究试件在不同的含钢率、约束拉杆设置参数以及偏心率下的力学性能。研究结果表明约束拉杆有助提高方形钢管混凝土偏压短柱的承载力和延性。同时,利用国内现有规程GJB 4142—2000、DBJ 13—51—2003以及CECS 159:2004对试件承载力进行计算,规程计算结果总体上低估了带约束拉杆方形钢管混凝土偏压试件承载力试验结果。采用带约束拉杆方形钢管混凝土的本构关系,利用条带法对试件承载力进行数值计算,计算结果与试验结果吻合良好。利用该数值方法对带约束拉杆方形钢管混凝土偏压柱进行参数研究,分析约束拉杆约束系数、钢材屈服强度、混凝土强度、截面含钢率以及长细比等主要参数对N/Nu-M/Mu曲线的影响,在此基础上提出适合带约束拉杆方形钢管混凝土偏压柱承载力简化计算公式。该简化公式计算结果与数值计算结果基本吻合,且总体上偏于安全。  相似文献   

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