压弯剪扭复合作用钢筋混凝土T形柱抗震性能研究

发布时间：2018-05-18 06:04

本文选题：压弯剪扭 + 钢筋混凝土　；参考：《广西大学》2017年硕士论文

【摘要】：为研究压弯剪扭复合受力钢筋混凝土 T形柱的抗震性能,以扭弯比、轴压比、肢高肢厚比变化参数,进行6个T形钢筋混凝土柱试件在恒定轴力反复弯剪扭复合作用下的加载试验。观察了试件的破坏过程和形态,获取了其扭矩-扭转角滞回曲线和荷载-位移滞回曲线,得到了试件的开裂点、峰值点和破坏点等特征参数。基于试验数据,详细分析扭矩对型钢混凝土柱的极限承载力、位移延性、层间侧移角、耗能能力、强度及刚度退化等抗震性能指标的影响。在试验的基础上,采用ABAQUS有限元软件对试验构件进行建模分析,对比了试验与模拟构件的滞回曲线及骨架曲线,经验证有限元模拟满足一般精度要求。在此基础上设计各工况下的试件15个,分别考虑了轴压比、扭弯比、纵筋直径、箍筋直径4个变化参数,分析了各变化参数对试件滞回曲线、骨架曲线、延性系数及初始刚度的影响,与试验结果基本相符,经试验和有限元模拟计算,主要得出以下结论:(1)根据扭弯比的不同,试件破坏形态分为弯形破坏、弯扭破坏及扭转剪切破坏,破坏时T形截面腹板底部混凝土被压碎,钢筋屈曲外露,腹板两侧混凝土被剪坏,其斜裂缝呈“X”状。(2)低周反复压弯剪扭复合受力T形柱的滞回曲线呈捏拢状的S形,滞回曲线不饱满;扭矩作用下,T形钢筋混凝土柱的延性减弱,扭矩的存在将加快裂缝的出现,但扭矩在一定程度上能增强试件的抗震耗能能力;轴压力的增加能够提高试件的初始刚度以及开裂荷载;肢高肢厚比的增大可提高试件的抗扭承载力及延性,但对刚度影响较小。(3)由ABAQUS增设的模型能够较为有效地对T形柱压弯剪扭复合受力进行模拟,其精度满足一般要求。通过拓展分析,发现纵筋直径的增加能有效提高试件的耗能能力,对试件抗弯承载力及延性提高有限;箍筋纵筋的增加对试件极限抗弯能力有所提升,但效果不明显。
[Abstract]:In order to study the seismic behavior of reinforced concrete T-shaped columns subjected to combined compression, bending and torsional forces, the variation parameters of torsional / bending ratio, axial compression ratio and limb height / thickness ratio are used to study the seismic behavior of reinforced concrete columns. The loading tests of 6 T-shaped reinforced concrete columns subjected to repeated bending, shear and torsion combined with constant axial force were carried out. The failure process and morphology of the specimen were observed. The torque-torsion angle hysteretic curve and load-displacement hysteretic curve were obtained, and the characteristic parameters such as crack point, peak point and failure point were obtained. Based on the experimental data, the effects of torque on the ultimate bearing capacity, displacement ductility, lateral displacement angle, energy dissipation capacity, strength and stiffness degradation of SRC columns are analyzed in detail. On the basis of the experiment, the ABAQUS finite element software is used to model and analyze the test component, and the hysteretic curve and skeleton curve of the test and simulation members are compared. It is verified that the finite element simulation meets the general precision requirement. On this basis, 15 specimens under different working conditions are designed, and four parameters are considered, including axial compression ratio, torsional bending ratio, diameter of longitudinal reinforcement and diameter of stirrups. The hysteretic curve and skeleton curve of each parameter are analyzed. The effect of ductility coefficient and initial stiffness is basically in agreement with the test results. The following conclusions are drawn by the experiment and finite element simulation calculation: 1) according to the different torsional bending ratio, the failure form of the specimen is divided into bending failure. Bending and torsional failure and torsional shear failure, when the T-section web bottom concrete is crushed, steel bar buckling exposed, concrete on both sides of the web is shearing, The oblique crack is "X" shape. (2) the hysteretic curve of T-shaped column under low cycle repeated compression, bending, shear and torsion is S-shaped, and the hysteretic curve is not full, and the ductility of T-shaped reinforced concrete column is weakened under the action of torque. The existence of torque will speed up the appearance of cracks, but to a certain extent, torque can enhance the seismic energy dissipation capacity of the specimen, and the increase of axial pressure can improve the initial stiffness and cracking load of the specimen. With the increase of the ratio of limb height to limb thickness, the torsional bearing capacity and ductility of the specimens can be improved, but the influence on stiffness is small. 3) the model added by ABAQUS can effectively simulate the compression, bending, shear and torsion forces of T-shaped columns, and its precision can meet the general requirements. Through expansion analysis, it is found that the increase of longitudinal reinforcement diameter can effectively improve the energy dissipation capacity of the specimen, and the flexural capacity and ductility of the specimen are limited, while the increase of stirrups increases the ultimate bending capacity of the specimen, but the effect is not obvious.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU375.3;TU352.11

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