板件弯剪屈服耗能支撑加固RC框架抗震性能研究

RESEARCH ON SEISMIC BEHAVIORS OF RC FRAME RETROFITTED BY BENDING-SHEAR YIELDING ENERGY DISSIPATION BRACE

  • 摘要: 为提高RC框架的抗侧能力并改善传统中心支撑受压屈曲的问题,将板件弯剪屈服耗能支撑布置于已有RC框架中。为研究该类支撑RC框架结构的抗震性能,设计制作了一榀单跨1/3缩尺的板件弯剪屈服耗能支撑RC框架并进行了低周往复加载试验,采用ABAQUS有限元软件分析了支撑类型、耗能元件连接方式、剪切板的高宽比与高厚比不同参数对其抗震性能的影响。结果表明:低周往复荷载作用下,结构主要通过剪切板、弯曲板发生塑性变形耗散能量,试件的破坏模式为耗能元件的连接焊缝处断裂、梁柱节点区混凝土剥落、左侧柱脚处混凝土压溃;整个试验过程中支撑杆件未发生屈曲,试件刚度、强度退化规律满足预期,整个结构表现出良好的耗能能力与延性。有限元分析表明:试件的抗震性能优于传统中心支撑框架;当剪切板、弯曲板采用焊接连接时结构的抗侧刚度与耗能能力均得到明显的提升;剪切板的高宽比变化对结构耗能能力影响不明显,而减小剪切板的高厚比可显著提高结构的承载能力与耗能能力。

     

    Abstract: For improving the lateral stiffness and avoiding the compressive buckling of traditional central braces in RC frames, a type of bending-shear yielding energy dissipation braces was developed and adopted in the RC frames. For investigating the seismic behaviors of this brace, a single-span 1/3 scaled RC frame with bending-shear yielding energy dissipation brace was designed and subjected to low reversed cyclic loading. ABAQUS finite element software was used to further analyze the influences of the type of braces, the connection type of energy-dissipating component, the height-to-width ratio of a shear plate, and the thickness-to-height ratio of a shear plate on the seismic behaviors of RC frames. The experimental results show that: under low reversed cyclic loading, the energy was mainly dissipated by shear plates and bending plates, and the failure modes include the tearing of the welds of the energy-dissipating components, the scaling of concrete at the column-beam joint, and crushing of concrete at the left foot of the column. Throughout the test, the brace did not buckle, the degradation of stiffness and strength of the specimen were expected, and the energy dissipation and ductility were superior. The numerical results indicate that: the seismic behaviors of RC frames retrofitted by the energy dissipation brace are better than that with traditional central brace; when the shear plate and bending plate are welded together, the lateral stiffness and energy dissipation capacity of the structure are significantly improved; the influence of the height-to-width ratio of shear plates on the energy dissipation capacity of RC frames can be negligible, and the bearing capacity and energy dissipation capacity increase with the decrease in the height-to-thickness ratio of shear plates.

     

/

返回文章
返回