一种考虑结构非线性的连续突风气弹响应计算方法

A calculation method of continuous gust aeroelastic response considering structural nonlinearity

连续突风气弹响应在工程中一般采用随机理论进行分析求解,通过将全机频响函数,与激励功率谱密度积分,即可得到各自由度均方根值。该方法基于频域线性求解,无法直接进行非线性响应分析。为此本研究基于匹配滤波器理论,提出了一套可考虑结构非线性的连续突风响应工程简化计算方法。通过引入突风滤波器,串联至全机气弹动力学系统,构成了连续突风的时域分析模型。针对所选取自由度的均方根值,通过匹配滤波器理论,计算得到一套各自由度“时间匹配”的响应,在此基础上,针对非线性结构模型,通过调整脉冲激励幅值,寻找最大的响应作为非线性结果,最终建立了一套适合于工程应用的、考虑结构非线性的连续突风响应计算方法。算例表明,本研究所建立的方法针对连续突风,可获得满足工程精度要求的各自由度“时间匹配”的响应,同时可用于结构非线性响应计算。

The continuous gust aeroelastic response is generally analyzed and solved using random theory in engineering.By integrating the frequency response functions of the airplane with the power spectral density of excitation,the root mean square value of each degree of freedom can be obtained.The method is based on the linear solution in the frequency domain,and the nonlinear response analysis cannot be directly carried out.Therefore,based on the matched filter theory,a simplified calculation method for continuous gust response considering structure nonlinearity is described in this paper.By introducing a gust filter,which is connected in series to the aeroelastic dynamic system of the whole plane,a time-domain analysis model of continuous gust is obtained.Based on the root mean square value of the selected degrees of freedom,the matched filter theory is used to calculate a set of the"time correlated"response for the other degree of freedom.On this basis,for the nonlinear structure model,by adjusting the impulse strength amplitude,the maximum response is found as the nonlinear result,and finally a nonlinear continuous gust response calculation method suitable for engineering and structural nonlinearity is established.The simulated results showed that the method established in this paper can be used to obtain the“time-correlated”response of each degree of freedom,and can also be used for structural nonlinear response calculation.