风荷激励下天线结构的随机振动分析
RANDOM VIBRATION ANALYSIS OF STOCHASTIC ANTENNA STRUCTURES UNDER WIND EXCITATION
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摘要: 研究随机天线结构的风激随机振动响应问题。考虑天线结构物理参数、几何尺寸和结构阻尼的随机性,在基于随机因子法对结构进行动力特性分析的基础上,从结构风激随机振动响应在频域上的表达式出发,利用求解随机变量函数矩的方法和求解随机变量数字特征的代数综合法,导出了随机天线结构在风荷激励下位移响应均方值和应力响应均方值的均值、方差和变异系数的计算表达式。以8米口径天线为例,分析了结构物理参数、几何尺寸和阻尼的随机性对天线结构风激位移响应均方值和应力响应均方值随机性的影响。Abstract: The random vibration analysis of stochastic antenna structures under wind excitation is studied in this paper.Based on the structural dynamic characteristic analysis in which the random factor method is utilized,the computational expressions of the mean value,variance and variation coefficient of the mean square value of the structural displacement and stress responses under wind excitations are developed.The random variable's functional moment method and the algebra synthesis method from the expressions of structural random response in the frequency domain are employed.The randomness of structural damping,physical parameters and geometric dimensions is considered.The influences of the randomness of the structural physical parameters and geometric dimensions on the randomness of the mean square value of the antenna structural displacement and stress responses are investigated through a sample antenna with 8 meter caliber.