基于等效单自由度体系的结构塑性耗能估计

Estimation of Structure Plastic Energy Based on Equivalent SDOF System Using Force Analogy Method

针对以某一阶振型为主的多自由度体系,基于等效单自由度体系基本假定和拟力法基本原理,建立了多自由体系和等效单自由度体系塑性耗能的关系公式,并以此提出估算多自由度体系塑性耗能的方法.以一个五层钢框架结构为例,利用MATLAB进行编程,输入4组不同的地震输入,分别获得了该结构与等效单自由度体系的塑性耗能曲线,并进行分析比较.结果表明,提出的基于等效单自由度体系估算结构塑性耗能,是一个概念清晰且计算简便的方法.

For multi-degrees-of-freedom（MDOF） system with one main vibration mode, the formulae of plastic energies between mMDOF system and equivalent single-degree-of-freedom （SDOF） system are established based on the assumption of equivalent SDOF system and the force analogy method. The method of estimating plastic energy for MDOF system is presented. A 5-story steel frame is analyzed to compare the plastic energies of multi-degree-of-freedom system and equivalent SDOF systems subjected to 4 different earthquake records. Results indicate that the method of estimating structure plastic energy by equivalent SDOF is clear in conception and accurate in application.