【作者】 庄晓勇；

【导师】 郭秉山；

【作者基本信息】 西安科技大学 ， 结构工程， 2006， 硕士

【摘要】 偏心支撑钢框架强度高、延性好，是适用于高烈度地震区的一种有效的抗侧力结构体系。目前国内外的研究多为单调荷载作用或把耗能梁段从框架中分离出来作为一个独立的构件进行循环荷载作用下的研究，这与耗能梁段在结构中的实际受力情况有较大的差异。从框架的整体抗震性能出发，系统深入地研究各参数对高烈度地震区广泛采用的K型偏心支撑钢框架整体抗震性能的影响，以更好地协调结构的承载力、刚度和延性这三者的关系，对于指导设计工作具有十分重要的现实意义。 本文考虑材料非线性和几何非线性，用有限元法首次对K型偏心支撑钢框架的整体受力性能进行了系统研究，真实地模拟了其在各种情况下的受力状态。通过对8个系列共33个试件的计算与分析，主要研究了耗能梁段的长度、耗能梁段腹板的厚度、框架的高跨比、支撑截面的大小、耗能梁段翼缘的厚度、耗能梁段加劲肋的间距、耗能梁段加劲肋的厚度、柱的轴力等参数对K型偏心支撑钢框架整体抗震性能的影响，得到的主要结论为：耗能梁段的长度在（1～1.26）M_p／V_p范围内取值时，偏心支撑钢框架的整体抗震性能最优；高跨比较小的结构，承载力与刚度较大，而延性与耗能性能相对较差，高跨比较大的结构则反之，框架的高跨比宜控制在0.5～0.7的范围内；为保证耗能梁段先行剪切屈服而支撑不屈曲，支撑的轴力增大系数η_br可按照不同地区的抗震设防烈度在1.4～1.6之间取值；对于长细比较小的支撑，其翼缘宽厚比应严一些，而将腹板高厚比控制在50以下则是比较合理的；支撑斜杆与横梁的连接焊缝发生断裂破坏的可能性较大，在施工中应对该处焊缝的焊接质量进行严格控制；在保证方便施焊的条件下应尽量选择间距较小的加劲肋，且加劲肋的厚度应取不小于0.8t_w为宜。 本文全面、系统、深入地分析了K型偏心支撑钢框架在循环荷载作用下的受力性能，对于修订有关规范、指导工程设计具有重要的参考价值，也为进一步研究其它类型的偏心支撑钢框架的抗震性能打下了良好的基础。更多还原

【Abstract】 Eccentrically braced steel frames have high strength and extensive good ductility. It is an effective lateral-resistant structure system which is appropriate for high seismic regions. At present, most of the research results in domestic and abroad on eccentrically braced frames are many for the monotonous load function or the links separates from the frame as an independent component carried on under the circulation load function in the research. As a result, the link’s actual load-bearing circumstances have remarkable difference. Therefore, embarks from the frame’s whole seismic-resistant performance, thoroughly and systematically studies the various parameters’ infulence to the seismic-resistant performance of the K shape eccentrically braced steel frames, by even better coordinates the relationship between the structure’s strength, rigidity and ductility has the extremely important practical significance regarding the instruction design work.This paper applies nonlinear （material and geometry） finite element method to systematically analyze the overall behaviors of K shape eccentrically braced steel frames under cyclic load for the first time. The load-bearing condition of K shape eccentrically braced steel frames in a variety of situations was really simulated. Through the calculation and analysis of 33 species of 8 series. The major parameters including links’ length ,thickness of links’ web, ratio of rise to span, section of brace, thickness of links’ flange , distance of links’ rib ,thickness of links’ rib, axial loading of column and so on are studied. The main conclusions are: （1） The link’s length which in the range of （1-1.26） M_p/V_p can make theframe’s whole seismic-resistant performance fully developed; （2） The smaller ratio of the frame’s height to span is, the larger its load-bearing capacity and rigidity, but the poorer its ductility and energy-dissipation. The larger ratio of the frame’s height to span is converse. So the ratio should be restricted to 0.5⁰.7; （3） In order to ensure the shear-yielding of link prior to the buckling of brace, the increasing coefficient of brace’s axial force η_br can be determined in the range of 1.4—1.6 according to different region’s seismic-resistant level; （4）更多还原