大跨度空间膜结构随环境风速模态变异性分析

ANALYSIS OF MODAL VARIABILITY OF THE LARGE SPAN SPATIAL MEMBRANE STRUCTURE WITH WIND SPEED BASED ON MEASURED DATA

由于膜结构具有较强的几何非线性特性,同时受流固耦合效应的影响使其动力参数识别难度加大,基于此点,本文利用小波包、随机减量技术和Laplace小波联合方法对大跨度空间膜结构的模态参数进行了基于实测数据的识别,并进一步分析了大跨度空间膜结构模态参数随风速的变化规律及其相关性,分析结果显示,该方法可有效识别膜结构的动力参数,且具有较好的抗噪能力,对于骨架支撑式膜结构而言,由于存在气动阻尼作用,其结构自身总阻尼较常规结构为大,这有利于结构气动稳定性,但该种结构并不属于风致敏感性结构。

It is very difficult to identify structural dynamic parameters due to geometric nonlinear properties and coupled fluid-structure effect. Therefore, in thispaper, modal parameters are identified based on measured data by methods of wavelet packet, random decrement technique and Laplace wavelet, the change regulation and relevance of modal parameters of the large span spatial membrane struc- ture to wind speed are analyzed. The result shows that this method can effectively identify structural dy- namic parameters and have better noise immunity, that the supporting membrane structure is not wind sensitive structure for bigger damping ratio than normal structures due to aerodynamic damping.