基于指数脉冲的气动导纳数值识别方法研究

Research on Numerical Identification Method of Aerodynamic Admittance Based on Exponential Pulse

气动导纳函数是桥梁抖振分析中的重要气动参数,通常利用风洞试验或数值模拟平台生成入口随机紊流风速或单频简谐来流进行识别。本文基于指数脉冲形式简单、频带宽的特点,提出了采用入口指数脉冲风速识别气动导纳的数值模拟方法。选取理想平板为研究对象,采用该方法进行气动导纳识别研究,并与理论Sears函数进行比较。研究结果表明,本文提出的数值识别方法具有可行性,当脉冲宽度大于600/s2、计算时间步长小于0.0005 s时,可以得到较为准确的结果。

Aerodynamic admittance function is an important aerodynamic parameter in the buffeting analysis of abridge.Wind tunnel test or numerical simulation platform is usually used to generate random turbulent wind velocity orsingle-frequency harmonic incoming flow for the identification of the aerodynamic admittance function.Based on thecharacteristics of simple form and wide bandwidth for exponential pulse,a numerical simulation method for identifyingthe aerodynamic admittance using the inlet exponential pulse wind velocity was presented.This method was used toidentify the aerodynamic admittance of the ideal plate and compare with the theoretical Sears function.The results showthat the proposed numerical identification method is feasible.When the pulse width is more than 600/s2 and thecalculation time step is less than 0.0005 s,more accurate results can be obtained.