灾害天气下大跨屋盖多模态随机离散风致响应研究

研究了具有空间相关性随机风荷载有色噪声过程的数学模型,讨论了用随机白噪声过程滤波生成脉动风荷载的方法。高阶振型对大跨屋盖随机风致响应的贡献不可忽略。本文根据模态解耦原理并结合精细时程积分法,提出了多模态随机离散精细积分法,推导了大跨屋盖风致响应与风效应系数的计算公式。通过大跨屋盖刚性和气弹模型风洞试验,计算了屋盖随机风致动力响应时程。同时研究了大跨屋盖的荷载风效应系数和位移风效应系数的分布情况,结果与有限元分析较吻合,验证了多模态随机离散精细积分法的正确性,证实了该方法是一种简便、快速、准确的大跨屋盖风致响应计算方法。

Random discrete wind-induced dynamic response of long-span roof in disaster windy environments

When wind flows around long-span flexible roofs,the flexible roofs will be exist large wind-induced buffeting responses.It is found that the contribution of higher vibration modes can not be ignored in the analysis of wind-induced dynamic responses for long-span roof structures.The characteristics of the random filtered white noise excitations such as wind load and the method generating a filtered white noise vector with spatial correlation using a white noise process have been investigated in the present study.The primary purpose of the study is to develope a Multi-Modal Precise Integration Method for Random Discrete Analysis(MPIMRDA) combined with the rigid and aeroelastic model wind tunnel test to estimate the wind-induced response of long-span roofs.The distribution of gust load factor and gust displacement factor on the flexible roof surface has been studied and compared,respectively.The results agree well with the finite element method.Finally,it is found out that the multi-modal precise integration method for random discrete analysis is really a valid method with simplicity,accuracy and fast calculation speed.