A frequency identification method suitable for all-phase spectral refinement of architectural structures

Abstract Short-time Fourier transformation (STFT) has been widely recognized as an intuitive time-frequency analysis method. However, its application in building structures is constrained by its low accuracy of low-frequency recognition in short data. Accordingly, an all-phase chirp-z transformation (AP-CZT) proposed for frequency recognition in building structures. Specifically, the autoregressive (AR) model, which has a proposed order determination algorithm, is used to solve the problem of data length limitation in the all-phase data process. Subsequently, an algorithm based on absolute inverse proportional function (AIP) is developed for post-refinement frequency correction. To verify its actual application, the ap-CZT method is used to analyze simulating finite element model and white noise feedback data from the actual shake table. The ap-CZT method is proven to be capable of correctly finding high-order frequencies. Moreover, it can accurately identify signal frequencies in short data. Therefore, the ap-CZT method can be applied as a frequency identification method in STFT in the field of building structures.