矩形截面超高层建筑风致脉动扭矩的数学模型

利用风洞试验结果,对矩形截面超高层建筑风致脉动扭矩数学模型进行研究。以厚宽比和风场类别为基本变量,采用最小二乘法得到了风致脉动扭矩系数根方差、功率谱密度、竖向相关性系数以及横风向基底弯矩-基底扭矩相干函数闭合计算公式。这些公式的计算结果与原始试验数据吻合较好,说明计算公式具有较高精度。此外,利用结构随机振动方法,用提出的公式以及直接采用试验风压数据计算一栋实际超高层建筑的扭转动力响应,对比了扭转广义力谱、顶层扭转响应谱以及扭转响应根方差等计算结果,对比结果表明两者吻合较好,从而验证了公式的适用性。

Mathematical model of torsional fluctuating wind force on rectangular super-tall buildings

In this paper,mathematical model of fluctuating torques acting on rectangular super-tall buildings were investigated based on wind tunnel test results.Using the nonlinear least-squares method,formulas of the RMS torsion moment coefficient,vertical torsion moment correlation coefficient,power spectrum density(PSD) of torsion moment and coherent function between crosswind base moment and base torques were fitted as the functions of side ratio of building cross-section and terrain category condition.Precision of the formulas was verified by comparing the measured data from wind tunnel test and calculated results.Furthermore,dynamic torsion responses of a real super-tall building were respectively computed by using the present formulas and by directly using the wind pressure data from the wind tunnel test.Results from the two different methods,including general torsion loads,response spectra and RMS values,match well,which could verify applicability of the present formulas.