共查询到17条相似文献，搜索用时 156 毫秒
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本文采用低强箍筋和高强箍筋的对比试验,对高强混凝上压弯构件进行了在反复荷载作用下的试验,得到了各试件的荷载-位移府回曲线,通过对荷载-位移滞回曲线、位移延性系数等的分析,研究了冷轧带肋钢筋作箍筋对高强混凝土柱延性的影响试验表明：高轴压比下的高强混凝土柱在高强度箍筋─—冷轧带肋钢筋、高配箍率下能获得很好的延性． 相似文献
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以2根焊接高强箍筋、高强混凝土柱试件为研究对象,进行低周反复水平荷载作用试验,研究体积配箍率的变化对柱滞回特性的影响.试验结果表明,高强混凝土柱体积配箍率较大的试件滞回曲线相对饱满,滞回环面积较大,累积滞回耗能大,吸收地震能量多,延性好.该研究结果对发展应用高强混凝土具有实际意义. 相似文献
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利用ANSYS模拟四根不同配箍率的高强混凝土轴压柱,分析了各柱的裂缝图和应力应变曲线。结果表明,随着配箍率的增加,柱的延性和承载力可以得到提高;较好的验证了文献中的箍筋作用机理。 相似文献
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使用通用有限元软件ABAQUS分析了钢材屈服强度、方钢管厚度、UHPC强度对高强方钢管约束UHPC短柱轴压性能的影响。首先使用ABAQUS对已有的普通钢管约束混凝土试验进行计算,结果与试验值基本一致。在此基础上建立了高强方钢管约束UHPC短柱模型,对比了不同参数下构件荷载-位移曲线、荷载-纵向应变曲线的变化特征。研究表明:构件前期刚度受混凝土强度影响很小,但由于增加混凝土强度使构件套箍系数降低,工作曲线下降段斜率增大,延性下降。钢管屈服强度的提高对构件的延性有很大改善,但对极限承载能力影响较小。核心混凝土强度是影响高强钢管约束UHPC短柱承载能力的主要因素,由于钢管不直接承担纵向荷载,仅对混凝土产生材料性能上的影响,钢管约束混凝土应看做混凝土的一种。 相似文献
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钢筋套箍加固砼柱后，能对其所包围的核心起约束作用，使之处于三轴受压的后力状态，具有较高的抗压强度和极限压缩变形，此即砼的“套箍强化”。钢筋箍对约束砼抗压强度的增强作用因配箍数量、间距和构造而变化。影响的主要因素之一为约束指标λt。通过模拟工程结构投入使用前先进行加固和使用过程中出现裂缝后进行加固两种工程状况试验，可得到钢筋套箍加固柱的受力性能和承载力建议计算公式。 相似文献
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砼框架结构延性的探讨 总被引：1，自引：0，他引：1
张志俊 《黄冈职业技术学院学报》2005,7(2):98-99
本文对砼框架结构延性的概念与重要性进行了总结。分析了影响砼框架结构延性的因素,总结了改善砼框架结构延性的措施,有利于结构设计人员加深对砼框架结构延性的理解。 相似文献
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彭燕 《杨凌职业技术学院学报》2014,(1):10-12
采用ANSYS软件进行了数值模拟,分别对比了三种型钢截面形式和i种轴压比对型钢高强混凝土柱的延性和耗能性能的影响。从计算结果可以看出,轴压比越小,延性系数越大,抗震性能越好;带翼缘十字形型钢柱的延性比不带翼缘十字形型钢柱的延性好。 相似文献
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通过对6根圆柱体钢筋混凝土柱的轴压试验，研究普通及高强混凝土柱的轴向受压性能．柱的混凝土强度为30MPa和60MPa．所考虑的主要因素为混凝土强度和箍筋用量．试验结果表明，箍筋间距越小，则柱承载能力越高，混凝土核心约束强度提高幅度越大．在相同的侧向约束下，高强混凝土柱的核心强度提高幅度低于普通混凝土柱．混凝土核心约束强度与非约束强度比率(fce^′/f′ce）及柱承载能力试验值与理论值之比(Ptest/P0)均与约束率ρs／fyt／f0′成正比． 相似文献
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为了提高柱的承载力、抗震性能和性价比,采用工程水泥基复合材料（ECC）材料替代钢筋混凝土（RC）柱柱根区域的混凝土形成 ECC ／RC 组合柱．基于已有的材料性能试验数据,采用 ATENA 有限元软件对 ECC 柱、ECC ／RC 组合柱及 RC 柱的压弯性能进行数值分析．研究了 ECC 柱和 ECC ／RC 组合柱的破坏机理,并与 RC 柱进行对比,进而探究 ECC 高度、轴压比和体积配箍率3个参数对 ECC ／RC 组合柱或 ECC 柱压弯性能的影响．结果表明：ECC 柱和 ECC ／RC 组合柱较 RC 柱具有更高的承载力、延性和抗裂能力;ECC高度在1．2h（h 为截面高度）左右的组合柱即可达到全 ECC 柱的性能效果;ECC 具有较高的抗剪强度,能显著减小箍筋的配置,便于施工和促进实际工程应用． 相似文献
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The seismic performance of four short concrete columns was investigated under low cycle and repeated loads, including the failure characteristics, hysteretic behavior, rigidity degeneracy and steel-bar stress. The influences of reinforcement strength, stirrup ratio and shear span ratio were also compared. Test results reveal that the restriction effect of stirrups can improve the peak stress, so the bearing capacity of specimen can be improved; for the high-strength short concrete column with high-strength stirrups, it was more reasonable to use ultimate displacement angle to reflect the ductility of the specimen, and the yield strength of high-strength stirrups should be devalued when calculating the stirrup characteristic value; the seismic performance of short column would be improved with the increase of volume–stirrup ratio and shear span ratio;the high-strength stirrups and high-strength longitudinal reinforcements did not yield when the load acting on the specimen reached the peak value, which brought adequate safety stock to these short columns. 相似文献
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Seismic ductility of very-high-strength-concrete short columns subject to combined axial loading and cyclic lateral loading 总被引：1，自引：0，他引：1
JIANG Rui JIA Jin-qing XU Shi-lang 《重庆大学学报(英文版)》2007,6(3):205-212
The seismic ductility of reinforced very-high-strength-concrete (VHSC) short columns was studied by combinatively applying axial load and low cyclic lateral load on specimens to simulate seismic impact. Twelve specimens with concrete compressive strength ranging from 95.6 MPa to 118.6 MPa and a shear-span ratio of 2.0 were tested for shear failure pattern and fear force-displacement hysteretic responses. Combinative application of axial load and low cyclic lateral load to VHSC short columns incurs shear failure. The displacement ductility is much smaller when the axial load ratio is larger;whereas a larger stirrup ratio is accompanied with a better displacement ductility. The relationship of displacement ductility factor, μ?, with stirrup characteristic value, λv, and test axial load ratio, nt, is μ?=(1 8λv)/(0.33 nt). By this relationship and relevant codes for aseismatic design, the axial load ratio limits for aseismatic design of reinforced VHSC (C95 to C100) short columns for frame construction are respectively 0.5, 0.6, and 0.7 for seismic classes I, II, and Ⅲ;corresponding minimum characteristic values of stirrups are calculated according to the required characteristic values of at least 1.273 times of experimental results. These data are very useful to aseismatic engineering. 相似文献
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Based on a series of previous studies, an experiment on the integral seismic behavior of a 1/3 scaled model of two-bay and three-story reinforced concrete frame with split columns at lower two stories is performed under cyclic loading. The original columns at lower two stories of the model frame are short columns and they are replaced by the split columns. The hysteresis curves between the horizontal cyclic load and the lateral displacement at the top of the model frame, indicate that under the cyclic loading, the model frame undergoes the process of cracking, yielding, and maxi-mum loading before being destroyed at the ultimate load. They also indicate that the model frame has better ductility, and the ratio of the ultimate displacement to the yielding displacement, reaches 6.0. The yielding process of the model frame shows that for the frame with split columns, plastic hinges are generated at the ends of beams and then the columns begin yielding while the frame still possesses the bearing and deformation capacity. The design idea of directly changing the short col-umn to long one in the reinforced concrete frame may be realized by replacing the short column with the split one. 相似文献
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Reinforced concrete （RC） columns lacking adequately detailed transverse reinforcement do not possess the necessary ductility to dissipate seismic energy during a major earthquake without severe strength degradation. In this paper, a new retrofit method, which utilized fiber-reinforced plastics （FRP） confinement mechanism and anchorage of embedded bars, was developed aiming to retrofit non-ductile large RC rectangular columns to prevent the damage of the plastic hinges. Carbon FRP （CFRP） sheets and glass FRP （GFRP） bars were used in this test, and five scaled RC columns were tested to examine the function of this new method for improving the ductility of columns. Responses of columns were examined before and after being retrofitted. Test results indicate that this new composite method can be very effective to improve the anti-seismic behavior of non-ductile RC columns compared with normal CFRP sheets retrofitted column. 相似文献
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基于 8个碳纤维布约束高强混凝土棱柱体试件的试验 ,研究了碳纤维布对提高高强混凝土抗压强度和改善其变形性能的作用 .试验发现 ,包裹碳纤维布可以提高试件的抗压强度 ,并有效地改善混凝土的变形性能 ,其效果随碳纤维用量的增加而更加显著 .在试验基础上 ,根据理论分析和对试验结果的整理 ,归纳出碳纤维布约束高强混凝土的应力 应变全曲线方程 .最后 ,利用提出的全曲线方程编制计算机程序 ,分析了包裹碳纤维布对提高高强混凝土压弯构件的强度和延性的作用 相似文献
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To investigate the seismic behavior of autoclaved aerated concrete load-bearing masonry wall（AACLMW）, a piece of control block wall without constructional measures and five pieces of block walls with different constructional measures were tested under low reversed cyclic loading which imitated low to moderate earthquake force. The seismic behavior of AACLMW with different constructional measures in terms of failure mode, hysteretic curve, deformation capacity and displacement ductility was studied and compared with that without constructional measures. The experimental results indicate that the constructional measures comprising constructional columns and horizontal concrete strips are effective for improving the seismic behavior of AACLMW. The study in this paper can provide a reliable experimental basis for further analysis and engineering application of AACLMW in the future. 相似文献