【作者】 周涛；

【导师】 肖岩；

【作者基本信息】 湖南大学 ， 防灾减灾工程及防护工程， 2007， 硕士

【摘要】 钢结构柱由于具有良好的抗震性能而广泛地应用于抗震区的抗弯框架中。但是当遭受地震作用时,在轴向力和水平往复荷载的作用下,经常发生局部和整体相关屈曲,导致承载力显著下降,并进而引起建筑物严重倾斜甚至倒塌。针对这一问题,研究者大多试图通过提出新的板件宽厚比来解决;然而在强烈地震作用下,即使对于板件宽厚比较小的钢构件也很难保证其不发生局部屈曲。本文在肖岩教授所提出的加横向约束的H型钢构件概念的基础上,对局部约束的轧制H型钢构件进行了研究。这种方法通过在钢构件可能产生局部屈曲的部位设置约束,以控制地震作用下钢构件塑性铰区局部屈曲的迅速发展,延缓其承载能力迅速下降的趋势,达到提高构件延性和耗能能力的目的。本文选用国产热轧宽翼缘H型钢进行了抗震性能的试验研究和有限元分析,主要进行了以下几个方面的工作:(1)简要回顾了轧制H型钢在国内的应用和研究现状,以及钢压弯构件在循环荷载作用下的研究进展。(2)针对地震作用方向的不确定性,按照侧向力沿弱轴和强轴作用平面内的不同设计制作了两组共九个大比例模型柱,其中三个模型柱沿弱轴平面内受弯,另外六个为强轴平面内受弯。(3)对所设计的模型柱进行了常轴力和水平往复荷载作用下的试验研究,在试验研究的基础上,考察了轧制H型钢柱在约束前后的破坏形态,详细分析了模型柱的承载能力、刚度、延性和耗能能力等,通过比较验证了施加约束对于改善H型钢柱抗震性能的有效性。探讨了外包钢环约束对局部屈曲的约束作用。(4)使用通用有限元软件ANSYS对本文所研究的模型柱进行了有限元分析,分析结果表明,所建立的模型能够较好的反映模型柱的受力性能和局部约束的作用,从而可以方便地进行局部约束的设计并预测约束柱的抗震性能。更多还原

【Abstract】 Steel columns have widespread applications in moment-resisting frames for their good seismic behavior. However, the steel columns are susceptible to damage caused by local and overall interaction buckling under constant axial load and cyclic lateral forces during earthquakes. Most of the researchers attempted to propose new width-thickness limit to solve the problems, however, it is difficult to avoid local buckling even for columns with small plate width-thickness ratio when subjecting to intense ground motion. Based on the concept of confined H-shaped steel members conceived by Xiao, this study investigates the seismic behavior of confined hot-rolled H-shaped steel columns. The concept aims at controlling the local buckling of the plates in the potential plastic hinge regions of an H-shaped steel column through applying additional confinement. A series of domestic Ma-gang hot-rolled H-shaped steel columns were tested and analyzed under constant axial load and cyclic lateral forces to validate the concept. The main work is summarized as follows:(1) A general overview of the application and research work on homemade hot-rolled H-shaped steel members is given; also a literature review of the experimental and analytical research work on seismic behavior of steel columns is presented.(2) Nine large-scale H-shaped steel model columns were designed to simulate typical columns in multi-story building in seismic regions. The nine model columns were divided into two groups, in which three were for weak axis bending and the others were for strong axis bending. There were two conventional model columns in each group without special confinement for providing benchmark date of seismic behavior of hot-rolled H-shaped steel columns.(3) All model columns were tested under constant axial load and cyclic lateral forces. The failure mode, strength degradation, stiffness degradation, ductility and energy dissipation were described in details to investigate the seismic behavior of the conventional and confined model columns. Compared with the conventional H-shaped steel model columns, the confined ones exhibited significantly improved seismic performance with large ductility.(4) The finite element analysis results indicate that the finite element model adopted in this study can effectively simulate the seismic behavior including loading capacity degradation and local buckling. The method can be used to design the local confinement and predict the seismic behavior of the confined columns proposed in this paper.更多还原