加权约束最小二乘法计算等效静力风荷载

Weighted Constrained Least Squares Method for Calculating Equivalent Static Wind Loads of Large-span Roof

摘要:

基于平均风压与脉动风压根方差相组合的分布模式,利用加权约束最小二乘优化方法计算等效静力风荷载,在计算时通过约束条件来限制等效荷载的大小,并通过引入权值因子确保等效荷载作用下典型响应的正确性.算例分析结果表明,该方法可用于计算大跨结构的多个目标峰值响应,克服了传统方法仅能等效单个响应的缺陷,对绝对值较大的目标响应等效精度较高,并且典型响应的等效精度要大于一般响应;同时可以有效控制等效荷载的大小,计算得到的等效荷载变化比较均匀,没有出现风压大小及方向剧烈变化的情况.

Abstract:

Based on the wind pressure distribution mode in which mean wind pressures are used together with RMS pressures,weighted constrained least squares method is adopted to calculate equivalent static wind loads for large-span roofs.In order to limit the range of the equivalent static wind loads,the constraint conditions are employed.Further,weighting factors are introduced to improve the accuracy of typical responses.The equivalent static wind loads in the paper can reproduce simultaneously several peak responses,whereas traditional methods just lead to equivalent loads which only target one certain response.Finally,the method is applied to a real large-span roof,and high accuracy is found for responses the absolute values of which are large to some extent.It is also found that typical responses have higher accuracy than non-typical ones for the usage of weighting factor.Meanwhile,the distribution of equivalent static wind loading calculated through the method is found to be reasonable,in which the gradient of wind loading are small and no oscillating results are observed.