基于变换空间法的结构参数识别及地震输入反演

Structural Parameter Identification and Seismic Input Inversion Based on Transform Space Method

针对地震作用下结构参数识别及未知输入反演问题,本研究提出一种仅观测部分自由度绝对加速度响应识别结构参数及反演未知输入的方法。首先,该方法基于变换空间法和最小二乘法,直接识别一层以上的结构阻尼和刚度参数;然后,利用识别得到的模态信息,求解一层刚度参数;最后,将动力方程转变到变换空间内,建立相邻采样时刻地震动输入的相关关系模型,提出一种简化的地震动输入反演算法。两层钢筋混凝土框架大尺度模型振动台试验及数值模拟结果表明:所提出的地震动输入反演方法对线性系统具有较高的精度及鲁棒性;对于非线性系统,反演得到的地震动输入时程能够较好地反映地震波低频特性,可进而用于区域结构及建筑群的抗震性能演绎分析。

Aiming at the problem of structural parameter identification and unknown input inversion under earthquake,this paper proposed a method of structural parameter identification and seismic input inversion using only partial absolute acceleration measurements as the observation.Firstly,based on transform space method and least squares method,structural parameters above the first story were identified directly.Then,the stiffness of the first story was identified based on the identified modal information.Finally,the dynamic equation was transformed into the transform space in which the correlation model of seismic input at adjacent sampling time was established and a simplified input inversion algorithm is presented.Results of numerical simulation and shaking table tests on a two-story reinforced concrete frame show that the proposed method has high accuracy and robustness for linear systems,and for nonlinear systems,the inversion results reflect the low-frequency characteristics of seismic input which can be used on seismic performance deductive analysis for regional structures and buildings.