基于三向敏感频率的单层球面网壳结构地震动强度参数分析

Analysis on a ground motion intensity measure of single-layer reticulated domes based on three-dimentional sensitive frequencies

选择合适的地震动强度参数可减小其与结构响应相关分析结果的离散性。以Kiewitt-8型单层球面网壳结构为研究对象,对算例结构进行谐响应分析,确定结构三个方向的敏感频率;提出基于三向敏感频率的地震动强度参数加速度谱Sa,3d。采用有限元软件ABAQUS对算例结构进行三向地震动作用下的增量动力分析,并对分析结果进行统计分析,从相关性和有效性两个方面对Sa,3d进行评价。结果表明:Sa,3d与单层球面网壳结构的地震响应具有更好的相关性,且具有较好的有效性,建议对单层球面网壳结构,采用Sa,3d作为地震动强度参数进行增量动力分析。

Selection of an appropriate ground motion intensity measure to be used in scaling or standardizing the ground motion records is of importance as it can be used to reduce the discreteness of the obtained responses for different ground motion records. Taking a Kiewitt-8 single-layer reticulated dome for example, a ground motion intensity measure in the seismic response analysis of single-layer reticulated domes was proposed by carrying out analysis on numerical model using ABAQUS. Sensitive frequencies of the numerical model in horizontal and vertical directions were obtained by carrying out the harmonic analysis. A three-dimentional ground motion basing spectral intensity measure Sa,3d on sensitive frequencies, was then proposed. Incremental dynamic analyses （IDAs） were carried out for the numerical model by using three-dimentional ground motions. Based on the linear regression of IDA results, Sa,3d was evaluated in terms of correlation and efficiency. The results indicate that this newly p correlated to the seismic responses of a single-layer reticulated dome more strongly, and roposed intensity measure is has better efficiency as well. Hence, Sa,3d is recommended to be used as the ground motion intensity measure for the IDA of single-layer reticulated domes.