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为研究钢筋锈蚀后再生混凝土框架节点的破坏特征和抗震性能,对钢筋未锈蚀、锈蚀而保护层未开裂、平均锈胀裂缝宽度为0．2mm及平均锈胀裂缝宽度为0．4mm四种情况下的再生混凝土及普通混凝土框架边节点,进行了低周反复荷载对比试验;观察节点的受力过程及破坏形态,分析试件的荷载一位移滞回曲线、承载能力、强度和刚度退化、延性以及耗能能力等力学特性．结果表明：相同锈蚀程度下,再生混凝土节点的强度比普通混凝土节点小,再生混凝土节点的刚度退化比普通混凝土节点严重,再生混凝土节点表现出更好的延性,再生混凝土耗能较普通混凝土耗能弱;随着钢筋锈蚀程度的增加,再生混凝土与普通混凝土节点的强度降低,刚度减小,延性减小,耗能能力降低． 相似文献
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In order to study the seismic behavior of frame with specially shaped columns,the hysteretic curve was analyzed based on a quasi-static test of a two-span,three-story frame with specially shaped columns.The top layer framework curve and the corresponding resilience model were obtained from the hysteretic curve.And the stiffness and strength degeneration were also investigated.The results indicated that the stiffness degeneration is not obvious,thus the frame with specially shaped columns has high earthquake-resistant behavior.The resilience model calculated from the test can provide reference for design and nonlinear finite element analysis. 相似文献
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In order to evaluate the seismic behavior of confined RC column-composite beam joints, five interior joints were tested under low cyclic reversed load. The weakening extent of flanges, the number of studs, and whether to reinforce weakened flanges were used as parameters in designing these five joints. Failure characteristics, hysteretic curves, skeleton curves, ductility, energy dissipation, strength degradation, and stiffness degradation were analyzed. The test results revealed that the steel beam flanges in the joints were equivalent to the tie rod. Weakened flanges resulted in poor seismic behavior; however, the seismic behavior could be improved by increasing studs and reinforcing weakened flanges. The joint steel plate hoops, equivalent to stirrups, did not yield when the maximum load was reached, but yielded when the failure load was reached for the joints with shear failure. Increasing stud-type joints and reinforcing flange-type joints ensured good seismic behavior and met project requirements. Based on the experimental results, the failure mechanism of the joints was discussed, and the shear capacity equations of the joints was presented. 相似文献
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Seismic behavior of steel reinforced ultra high strength concrete column and reinforced concrete beam connection 总被引：1，自引：1，他引：0
To investigate the seismic behavior of connections composed of steel reinforced ultra high strength concrete （SRUHSC） column and reinforced concrete （RC） beam, six interior strong-column-weak-beam connection specimens were tested subjected to reversal cyclic load. Effects of applied axial load ratio and volumetric stirrup ratio on ductility, energy dissipation capacity, strength degradation and rigidity degradation were discussed. It was found that all connection specimens failed in bending in a ductile manner with a beam plastic hinge. The ductility and energy dissipation capacity increased with the decrease of applied axial load ratio or increase of volumetric stirrup ratio. The displacement ductility coefficient and equivalent damping coefficient lay between those of steel reinforced ordinary concrete connection and those of reinforced concrete connection. The applied axial load ratio and volumetric stirrup ratio had less influence on the strength degradation and more influence on the stiffness degradation. The stiffness degraded sharply with the decrease of volumetric stirrup ratio or increase of applied axial load ratio. The experimental results indicate that SRUHSC column and RC beam connection exhibited better seismic performance and can provide reference for engineering application. 相似文献
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通过对锈蚀钢筋混凝土构件的低周反复荷载试验，讨论了钢筋锈蚀对混凝土构件的滞回曲线、骨架曲线、刚度、延性、耗能能力、承栽力等不利影响，提出了锈蚀钢筋混凝土构件抗剪承栽力与抗弯承载力计算表达式。 相似文献
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利用有限元软件ABAQUS对纯钢框架试件、冷弯薄壁型钢组合墙体试件、钢框架-冷弯薄壁型钢组合墙体试件、覆双面OSB板的钢框架-冷弯薄壁型钢组合墙体试件进行水平低周往复荷载作用下研究,分析了试件的滞回曲线、骨架曲线、抗侧刚度、延性和耗能等。结果表明,钢框架与冷弯薄壁型钢组合墙体有明显的组合效应;冷弯薄壁型钢组合墙体能明显增强钢框架结构的承载力、刚度、延性和耗能能力;覆双面OSB板钢框架-冷弯薄壁型钢组合墙体结构抗震性能较不覆板的钢框架-冷弯薄壁型钢组合墙体结构抗震性能好。 相似文献
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The seismic behaviors of an integral concreting frame, a light steel storey-adding frame and a storeyadding frame strengthened with carbon fiber reinforced polymer(CFRP)were investigated under low-cycle and repeated load(scale 1∶3). The failure characteristics, hysteretic behavior, rigidity degeneracy, deflection ductility and energy-dissipation capacity of the three specimens were compared. The test results reveal that chemicallybonded rebar technique can meet the requirements of storey-adding engineering. The carrying capacity, the deflection ductility, the energy-dissipating capacity and seismic performance of the light steel storey-adding frame are higher than those of the integral concreting frame, and they are the highest in the storey-adding frame strengthened with CFRP. 相似文献
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刘如月薛潘荣颜桂云 《福建工程学院学报》2020,(6):553-559
为实现装配式结构震损后能快速修复以恢复使用功能,提出一种带可恢复功能节点的装配式框架结构体系。利用ABAQUS 有限元软件对可恢复功能节点进行数值模拟,探讨可恢复功能节点的作用机理,并将可恢复功能节点布置到装配式框架结构中形成可恢复功能装配式框架结构,考察整体结构的受力机理,可更换耗能铰、装配式节点核心区与梁柱部件的失效演化规律。结果表明,节点的失效主要是由于可恢复功能节点在削弱钢板处的损伤累积引起的断裂导致?与现浇混凝土框架及节点加强型现浇混凝土框架相比,可恢复功能装配式框架的承载能力更高、延性更好,通过可更换耗能铰的塑性变形耗散能量大幅度提高了结构的耗能能力,且结构的损伤破坏集中在削弱钢板上,有效地避免了预制梁柱和节点核心区的损伤。震后通过更换损伤耗能元件即可恢复结构的使用功能,实现了损伤可控和震后功能可恢复的抗震设防理念,具有广泛的应用前景。 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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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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采用有限元分析方法考察梁和柱的截面尺寸、角型连接件尺寸、铆钉直径及端距等对节点性能的影响,根据计算得到的弯矩-转角曲线拟合出三参数模型中形状系数n 值的近似计算公式。结果表明,柱翼缘厚度和角型件厚度对节点初始刚度和极限承载力影响显著,梁高和铆钉端距的影响次之。形状系数建议公式计算结果与试验结果吻合较好,可为该类连接节点设计方法提供理论依据。 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
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通过三个H型铜梁柱顶底角铜、腹板双角铜连接节点原型试件在往复荷载作用下的试验研究，分析带双腹板角铜的顶底角铜的连接刚度、承载能力和延性特征，得出腹板角铜对连接的承载力有明显改善的结论，并建议在计算连接抗弯承载力时应考虑腹板连接的影响． 相似文献
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A 9-story concrete-filled steel tubular frame model is used to analyze the response of joints due to sudden column loss. Three different models are developed and compared to study the efficiency and feasibility of simulation, which include substructure model, beam element model and solid element model. The comparison results show that the substructure model has a satisfying capability, calculation efficiency and accuracy to predict the concerned joints as well as the overall framework. Based on the substructure model and a kind of semi-rigid connection for concretefilled square hollow section steel column proposed in this paper, the nonlinear dynamic analyses are conducted by the alternate path method. It is found that the removal of the ground inner column brings high-level joint moments and comparatively low-level axial tension forces. The initial stiffness and transmitted ultimate moment of the semi-rigid connection are the main factors that influence the frame behavior, and their lower limit should be guaranteed to resist collapse. Reduced ultimate moment results in drastic displacement and axial force development, which may bring progressive collapse. The higher initial stiffness ensures that the structure has a stronger capacity to resist progressive collapse. 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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Seismic force modification factor for ductile structures 总被引：3，自引：0，他引：3
INTRODUCTION In codes for seismic design of buildings of many developed countries, elastic response spectra are adopted to calculate the base shear forces. For exam-ple, the base shear defined in Japan code 1997 is: FEK=DsFesC0ZAiRtW (1) where Rt is the elastic design spectrum; Ds is the structural coefficient changing among 0.25 to 0.50 to take account of different ductility of different struc-tures; W is the total weight of a structure; the others are site coefficient, irregular… 相似文献
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为了更好地保护古建筑,采用试验方法研究了CFRP加固古建筑榫卯节点后的抗震性能.基于某古建筑实际尺寸,制作了1:8缩尺比例的木结构空间框架模型,并考虑梁柱连接为燕尾榫形式.进行了低周反复加载试验,包括3组未加固构架试验和2组CFRP加固试验.基于试验相关数据,获得了节点的弯矩-转角滞回曲线和骨架曲线,并对比分析了节点加... 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