摘要
提出根据风振响应特征,构造多目标等效静风荷载的荷载基本向量,当脉动风效应中以背景响应为主、且存在显著主导本征模态时,选择本征模态作为荷载基本向量;当以共振响应为主、且存在显著主导振型时,将主导振型惯性力作为荷载基本向量;当风效应中无显著主导本征模态或者无显著主导振型时,将屋面上表面各点法向分别作用单位力作为荷载基本向量。根据最小二乘法得到这些基本向量的组合系数,保证在该等效静风荷载下,结构所有关键位置响应与实际动力响应极值间的误差最小。并将该方法应用于平面桁架和单层球面网壳,验证了该文所述方法的计算精度。
Fundamental loading vectors are selected to express equivalent static wind loads （ESWL） for multiple targets, on the basis of wind-induced response characteristics. The eigen-mode of wind loads is selected when the background response is much bigger than the resonant response and one dominant eigen-mode exists in the response. Modal inertial force is selected when the resonant response is much bigger than the background response and one dominant structural mode exists in the response. Unit loading vectors at each node along the normal direction of the roof surface are selected as fundamental loading vectors, if no dominant mode exists in the response. Combination factors of these fundamental loading vectors are obtained with a least square approximation method. This method is employed to study ESWLs of a plane truss and a single-layer dome, and the results show that the presented method has good calculation precision.
出处
《工程力学》
EI
CSCD
北大核心
2012年第11期152-157,164,共7页
Engineering Mechanics
基金
国家自然科学基金项目(50938008
50808010)
北京市自然科学基金项目(8112023)
中央高校基本科研业务费专项资金项目(2011JBM270)
关键词
大跨屋盖结构
等效静风荷载
风振响应
本征模态
结构振型
long span roofs
equivalent static wind loads
wind-induced response
eigen-mode
structural mode
