摘要
基于性能的抗震设计理论涉及如何简便而合理地确定结构在指定强度地震下的弹塑性位移需求。本文给出了利用延性需求谱求解结构位移需求的一般步骤:借助模态Pushover分析将多自由度体系分解为几个非线性单自由度体系,以考虑各阶振型的影响;利用延性需求谱计算对应模态的等效单自由度体系的延性及位移需求,并以一定方式组合转化为多自由度体系位移需求。最后,通过算例分析表明:利用延性需求谱求解结构位移需求是一种具有一定精度可为工程接受的简便方法,在基于性能的抗震设计中具有较好的应用前景。
Performance-based seismic design involves how to calculate inelastic displacement demand of structures under specified intensity earthquake in concise and reasonable way. In this paper, the basic solving process of structural inelastic displacement demand adopting ductility demand spectra is put forward. Firstly, the MDOF system is decomposed into several inelastic SDOF systems using modal pushover analysis, and the higher mode effect can be considered by this means. Secondly, the ductility and displacement demand of equivalent SDOF system can be solved by utilizing ductility demand spectra, and combined correspondence modal displacement can revert to the displacement demand of MDOF system. With the analysis of examples, it is shown that the procedure to get inelastic displacement demand of structures employing ductility demand spectra may be used in engineering as a simple and effective method. This method has application potential in performance-based seismic design.
出处
《地震工程与工程振动》
CSCD
北大核心
2004年第1期30-38,共9页
Earthquake Engineering and Engineering Dynamics
基金
国家自然科学基金资助项目(50025821)
上海市重点学科建设资助项目
