This study used a wavelet-based technique with variable modal scales to achieve the identification of modal parameters. Combined with the correlation technique or random decrement algorithm, the stationary response can be transformed into a quasi-free response, which can be employed to estimate the number of excited modes of structures and determine the modal scale corresponding to the major modes solely through the wavelet analysis. An improvement method is also proposed for the amplitude maximum method (AM) in the determination of modal scale obtained from the ridges in the time–frequency wavelet spectrum. The amplitude accumulation method can be employed to more accurately estimate the corresponding scale of each mode and avoid the disadvantage of low robustness of the conventional AM method for measurements contaminated with noise. Numerical simulations and an experimental validation of a realistic 6061-T6 aluminum alloy beam are used to demonstrate the effectiveness and robustness of the proposed method to identify modal parameters from the response of structures subjected to stationary ambient excitation under noisy conditions.

这项研究使用具有可变模态比例的基于小波的技术来实现模态参数的识别。结合相关技术或随机减量算法，可以将平稳响应转换为准无响应，仅通过小波就可以估计结构的激发模态数量并确定与主要模态相对应的模态尺度分析。还提出了一种改进方法，用于确定从时频小波频谱中的脊线获得的模态尺度时的振幅最大值方法（AM）。可以采用幅度累积方法来更准确地估计每种模式的相应比例，并避免传统AM方法用于被噪声污染的测量的鲁棒性低的缺点。