Flutter design is important for the design of new aircraft types, for which flutter tests are an important verification measure. Atmospheric turbulence excitation is a common form of excitation in flutter flight tests. The modal parameter estimation of the turbulence response is a key aspect to ensure accurate data processing of flutter test results. Atmospheric turbulence excitation acts on the structural system, and the turbulence response thus simultaneously contains both the randomness of the excitation signal and the determinism of the structure system. In view of the turbulence response characteristics, this paper addresses the incoherence of atmospheric turbulence excitation and the orthogonality of the frequency domain from a multichannel response. The turbulence response is used to perform modal parameter identification in the frequency domain. The power spectral density matrix can be calculated from the multichannel turbulence response using the periodogram method. Singular value decomposition is then performed on the power spectral density matrix at each spectral pin based on the orthogonality of the frequency domain. The maximum singular value of each spectral pin forms a curve over the entire frequency band, which is the autopower spectral density function of the system, the system is directly identified at the frequency domain using the polynomial fitting in the frequency domain, and the modal parameters (frequency, damping ratio) are calculated according to the fitted transfer function. This paper verifies the theoretical feasibility of the proposed method using simulation data. The engineering applicability is verified based on the turbulence response from the flutter flight test of a certain aircraft type.

中文翻译：

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湍流颤振试验多通道结构响应模型参数估计方法

颤振设计对于新机型的设计很重要，颤振测试是重要的验证措施。大气湍流激励是颤振飞行试验中常见的激励形式。湍流响应的模态参数估计是确保对颤振试验结果进行准确数据处理的关键方面。大气湍流激励作用于结构系统，湍流响应同时包含激励信号的随机性和结构系统的确定性。鉴于湍流响应特性，本文从多通道响应中解决了大气湍流激励的不相干性和频域正交性问题。湍流响应用于在频域中进行模态参数识别。可以使用周期图方法从多通道湍流响应计算功率谱密度矩阵。然后基于频域的正交性对每个频谱引脚处的功率谱密度矩阵进行奇异值分解。每个谱针的最大奇异值在整个频带上形成一条曲线，即系统的自功率谱密度函数，在频域使用多项式拟合直接在频域识别系统，模态参数（频率，阻尼比）根据拟合的传递函数计算。本文利用仿真数据验证了所提方法的理论可行性。