[书]PERFORM-3D原理与实例 – 第16章 – Pushover 分析原理与实例 ( Chapter 16 Pushover Analysis Theory and Tutorial )

Pushover 分析方法又称为静力弹塑性分析方法或静力非线性分析方法,是一种以结构顶部的侧向位移作为整体抗震性能判据的结构抗震性能评估方法,它将非线性静力分析与反应谱理论紧密结合起来,用静力分析的方法预测结构在地震作用下的动力反应和抗震性能,在基于性能的抗震设计中得到了较为广泛的研究与应用。我国的《高层建筑混凝土结构技术规程》(JGJ 3-2010)第3.11.4条明确指出[1],高度不超过150m的高层建筑可采用静力弹塑性分析方法进行结构的抗震性能评估。通过Pushover分析进行结构抗震性能评估的基本步骤如下[2]:(1)建立结构的Pushover曲线;(2)确定用于评估的地震动水准;(3)选择用于评估的性能水准及其容许准则;(4)采用特定的方法求取结构性能点并进行结构性能评估。常用的Pushover分析方法主要包括ATC-40[3]采用的“能力谱法”、FEMA 356[4]推荐的“目标位移法”、FEMA 440[5]提出的“等效线性化”和“位移修正”两种方法等。其中能力谱法是最早提出的Pushover分析方法,本章主要介绍能力谱法的基本原理及其在PERFORM-3D[6,7]中的应用。

[Tool] Pushover Performance Point Solution Program [Pushover 分析性能点求解程序][Based on FEMA 440]

[Tool] 基于FEMA 440等效线性化法 Pushover分析方法 的性能点求解程序。A program for the Solution of Pushover Performance Point based on FEMA 440 Equivalent Linearization Method. FEMA 440等效线性化方法是众多Pushover分析方法中的一种,是ATC-40能力谱法(Capacity-Spectrum Method )的一种改进,其基本原理如下图所示。( Equivalent linearization procedure of FEMA 440 is a modification to the Capacity-Spectrum Method (CSM) of ATC-40. )When equivalent linearization is used as a part of a nonlinear static procedure that models the nonlinear response of a building with a SDOF oscillator, the objective is to estimate the maximum displacement response of the nonlinear system with an “equivalent” linear system using an effective period, Teff, and effective damping, βeff (see Figure above). The global force-deformation relationship shown in the above figure for a SDOF oscillator in acceleration-displacement response spectrum (ADRS) format is termed a capacity curve. The capacity curve shown in the above figure is developed using the conventional procedures of FEMA 356 or ATC-40. The effective linear parameters are functions of the characteristics of the capacity curve, the corresponding initial period and damping, and the ductility demand, µ.