- 摘 要
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(上海长福工程结构设计事务所, 上海 200031)
[摘要]应用解析解和能量法讨论了等截面均质悬臂杆模型以及基于顶点位移等效原理的等效刚重比的理论缺陷和不确定性,明确指出带P-Δ杆或P-Δ柱的力学模型是对结构进行P-Δ效应数值分析的最理想模型。按我国规范,提出按小震和大震二阶段进行稳定设计的学术观点。建议在基于承载力的小震设计中,将使用有限元法得到的屈曲因子直接作为判别结构整体稳定性的设计指标,使用“直接法”确定放大的位移和弯矩。在基于变形的大震设计中,同时考虑材料非线性和构件几何非线性,计算塑性(广义)变形,评估结构的抗震性能目标。
[关键词]屈曲分析; P-Δ效应分析; 材料非线性; 几何非线性
中图分类号:TU398.2 文献标识码:A 文章编号:1002-848X(2014)02-0001-07
P-Δ effect analysis and stability design of long-period super high-rise RC buildings
Fu Changsheng, Zhou Lilang, Zhang Xiaoyong
(Shanghai ChinaFu Structural Design Inc., Shanghai 200031, China)
Abstract: By using the analytical solutions and energy method, the uncertainties and theoretical discrepancies were discussed of the model of homogeneous cantilever strut with uniform section and equivalent rigidity-to-gravity ratio based on vertex displacement equivalent principle. It is concluded that the model with P-Δ strut or P-Δ column is the most reasonable model to carry numerical analysis of the P-Δ effects. In accordance with the codes in China, it is proposed that the stability design could be done in two stages of frequent and rare earthquakes. The suggestions are made that in the seismic design under frequent earthquake based on bearing capacity, the buckling factor obtained by FEM could be used to judge the overall stability of the structure and the magnified lateral displacements and moments could be determined by ‘direct method’. In the seismic design under rare earthquake based on deformation, both of material and geometrical nonlinearity should be considered to calculate plastic deformation and estimate the performancebased seismic design objectives of the structure.
Keywords: buckling analysis; P-Δ effect analysis; material nonlinearity; geometrical nonlinearity
作者简介:扶长生,教授级高级工程师,Email:cfstruct@vip.sina.com。
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