大跨屋盖结构风振响应参数灵敏度分析

PARAMETER SENSITIVITY ANALYSIS OF WIND-INDUCED RESPONSE OF LONG-SPAN ROOFS

对典型大跨屋盖结构风振响应开展参数灵敏度研究,目的是定量评估各种不确定因素对结构风振响应不确定性的贡献率,获得不确定性在风荷载与风振响应间的传递规律。首先结合Sobol’方差分解法和拉丁超立方抽样技术建立适用于大跨屋盖结构的全局灵敏度分析方法,通过多次采样风洞试验获得大量脉动风荷载时程,作为灵敏度分析的输入变量。合理建立结构参数概率统计模型,分别应用局部和全局灵敏度分析方法对典型大跨屋盖结构极值风振响应进行了参数灵敏度分析,研究发现:多个参数共同随机变化时,结构极值风振响应近似服从广义极值分布;结构风振响应的不确定性主要受风荷载不确定性控制;结构风振响应的参数灵敏度与共振响应在总响应中的比重有关,共振响应占比越大,结构对风荷载越敏感。

The parameter sensitivity analysis of the wind-induced response of a long-span roof is performed in order to quantify the strength and relevance of the inputs in determining the variation in a wind-induced response. The propagation law of uncertainty between a wind load and a wind-induced response is discussed. First, repeated wind tunnel tests are carried out to obtain a large amount of fluctuating wind pressure time histories, which could be the input variable of sensitivity analysis. Then probability-statistic models of structural parameters are constructed reasonably. The parameter sensitivities to wind-induced responses are systematically analyzed by combining the Sobol' method and Latin hypercube sampling technique. It is found that the extreme wind-induced response approximately obeys a generalized extreme-value distribution. The uncertainty of wind-induced responses is mainly controlled by wind load uncertainty. The parameter sensitivity to a wind-induced response is related to the ratio of the resonant response to the total response. The sensitivity value is larger with the increase of the ratio.