多风向多目标等效静风荷载分析方法及应用

Method and application of equivalent static wind loads for multiple targets and wind directions

针对大跨空间结构中多振型参与风振响应特点和工程应用需要,提出针对多个风向的多目标等效静风荷载分析方法。根据所有风向的平均风荷载(或者风振响应极值)分布之间的相似性指标,将所有风向分为若干个风向区,计算各风向区的风振包络响应;在每个风向区内,选择平均风荷载分布和结构主导振型惯性力作为构造多目标等效静风荷载的基本向量,根据最小二乘法,得到基本向量的最优组合系数,从而得到针对多个风向、多个等效目标的等效静风荷载。将该方法用于某大型科技新馆,分析结果表明:根据各风向下屋面平均风压系数分布间的相关系数,36个风向角仅需分成3个风向区,且各风向区等效静风荷载作用下的静力响应与实际动力响应包络响应吻合较好,验证了所提方法的计算精度和工程应用的便利性。

A new method to analyze equivalent static winds simultaneously reproducing all largest load effects（named as multiple equivalent targets） for multiple wind directions was proposed according to the characteristics of wind-induced response and the convenience of engineering application.The procedure of this method was： according to the correlation coefficients among the distributions of wind-induced response or mean wind pressure coefficients of all wind directions,all wind directions were divided into several wind direction zones,and the envelope response value of each wind direction zone was calculated;mean wind pressure coefficient distributions of the wind direction zone and dominating vibration modes were selected as basic vectors to express equivalent static wind loads for multiple targets and multiple wind directions,and the least square approximation method was employed to calculate the combination factors of these basic vectors.Thus,equivalent static wind loads were obtained.Furthermore,this method was applied to one long-span museum structures.The results show that： all 36 wind directions are divided into three wind direction zones according to the correlation coefficients among the mean wind pressure coefficients distributions;structural responses under a single equivalent static wind distribution agrees well with envelope response values under actual dynamic wind loads for multiple wind directions at the same time,which verifies the precision and convenience of the proposed method.