装配式斜支撑节点钢框架结构桁架梁等代分析研究

RESEARCH ON EQUIVALENT ANALYSIS OF TRUSS BEAMS OF PREFABRICATED STEEL FRAME STRUCTURE WITH DIAGONAL BRACING JOINTS

针对装配式斜支撑节点钢框架结构桁架梁杆件数量多、难于结构计算的问题,提出一种简化计算方法,将钢桁架梁根据等刚度、等高度、等翼缘的原则等代为实腹型工字钢梁。分别考虑简支梁施加均布线荷载、简支梁施加跨中集中荷载、悬臂梁施加均布线荷载和悬臂梁施加自由端集中荷载四种边界条件,反算得到5组等代梁截面。采用SAP 2000建立起一栋20层的装配式斜支撑节点钢框架建筑的实际结构计算模型和等代模型进行结构分析,对模态周期、层位移、层间位移角、剪重比、刚重比等关键指标进行对比。结果表明:采用简支梁施加均布线荷载边界条件反算得到的等代模型计算结果与实际模型最为吻合,可用于装配式斜支撑节点钢框架结构及类似结构的整体分析和设计。

Due to the difficulty to do structural calculation and the big quantity of truss beam members in the prefabricated steel frame structure with diagonal bracing, this paper proposed a simplified calculation method by equating steel truss beams with solid I-steel beams according to the principle of equal stiffness, equal height and equal flanges.5 equivalent beam sections figures were obtained by considering the 4 boundary conditions： simply supported beam subject to uniform loads, simply supported beam subject to point loads at mid-span, cantilever beam subject to uniform loads and cantilever beam subject to point loads at free end.SAP 2000 was applied to build an actual structural calculation model and equivalent ones of a 20-storey prefabricated steel frame structure with diagonal bracing joints.The structural calculation was performed to give a comparison of the key indexes such as mode periods, drift, inter-story drift angle, shear-weight ratio, rigidity-to-gravity ratio and so on.The best match happened between the results achieved in the boundary condition of simply supported beam subject to uniform loads and the actual model.It was proved that this method could be used in integral structure analysis and design for the prefabricated steel frame structure with diagonal bracing and other similar structures.