不同跨度比下腹板双角钢连接抗倒塌性能研究

发布时间：2018-06-21 01:04

本文选题：钢框架 + 腹板双角钢连接　；参考：《工程科学与技术》2017年04期

【摘要】：基于备用荷载路径法,以腹板双角钢连接的3个不同跨度比(1.0∶0.6、1.0∶1.0、1.0∶1.4)两跨三柱型钢框架梁柱子结构为研究对象,通过单调静力加载试验和数值分析探究了其在连续倒塌条件下的破坏模式、力学形态、抗力机制和节点失效机理。结果表明,试件破坏均为失效柱与梁相连的两侧角钢因受拉在螺栓孔处发生断裂,且梁轴力、梁端节点转角以及角钢尺寸等是影响角钢肢断裂破坏的主要因素。3个试件具有相似的变形形态和破坏模式,其最大荷载峰值接近,但最大荷载峰值对应的失效柱水平位移随跨度比的增大而依次减小。对不等跨试件,变形较大时梁柱子结构因短梁梁端转角远大于长梁,使得内力重分布时线刚度较大的短梁将承担较多的水平荷载而先发生破坏,且不等跨试件的梁端塑性转角大于等跨试件。3个试件的抗力机制发展过程均可划分为梁机制与悬链线机制的混合阶段、悬链线机制阶段,且悬链线机制的充分发挥需要梁柱间具有可靠的拉结力。通过数值分析,考虑梁柱子结构材料和几何非线性、接触非线性及钢材的断裂,其结果与试验吻合较好;在此基础上,深入分析了周边构件对该连接梁柱子结构的边界约束作用,当边柱刚度足够时,周边构件的轴向约束对梁柱子结构抗倒塌承载力的影响不大。
[Abstract]:Based on the method of spare load path, a two-span, three-column beam column structure with three different span ratios of 1.0: 0.6: 1.0: 1.0: 1.0: 1.4 is studied. By means of monotone static loading test and numerical analysis, the failure mode, mechanical morphology, resistance mechanism and failure mechanism of joints under continuous collapse were investigated. The results show that the failure of the specimens is due to the fracture of the two sides of angle steel connected to the beam by tension at the bolt hole and the axial force of the beam. The angle at the end of the beam and the size of the angle steel are the main factors affecting the fracture failure of the angle steel limb. The three specimens have similar deformation patterns and failure modes, and the maximum load peak value is close to that of the three specimens. However, the horizontal displacement of the failure column corresponding to the peak value of the maximum load decreases with the increase of the span ratio. For the specimen with unequal span, when the deformation is large, the Liang Zhu substructure will bear more horizontal loads and destroy first because the corner angle of the short beam is much larger than that of the long beam, so that the short beam with larger linear stiffness will bear more horizontal loads when the internal force is redistributed. The plastic rotation angle of beam end of unequal span specimen is greater than that of equal span specimen. The development process of resistance mechanism of three specimens can be divided into mixed stage of beam mechanism and catenary mechanism stage. And the full use of catenary mechanism requires a reliable binding force between Liang Zhu. Through numerical analysis, considering the structural material and geometric nonlinearity of beam and column, the contact nonlinearity and the fracture of steel, the results are in good agreement with the test. The effect of the peripheral member on the boundary constraint of the beam-column structure is deeply analyzed. When the stiffness of the edge column is sufficient, the axial constraint of the peripheral member has little effect on the collapse bearing capacity of the Liang Zhu substructure.
【作者单位】：西安建筑科技大学土木工程学院;
【基金】：国家自然科学基金青年科学基金资助项目(51308442);国家自然科学基金面上项目资助(51678476)
【分类号】：TU391

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