Morlet-wave-based modal identification in the time domain

Single-Pixel Optical-Flow-Based Experimental Modal Analysis

“…The Morlet-wave (MW) modal identification method is based on the Morlet-wave integral to perform overdetermined modal identification from the free-response measurements in the time domain [35]. The Morlet-wave integral 1 is defined with:…”

“…If the analysed signals have closely spaced harmonic components, more attention is needed in the selection of the MW function parameters 𝑛 and 𝑘 [35].…”

“…To provide the basis for identifying the modal parameters, the MW integral of the free response ( 4) is derived analytically by paying attention to the theoretical limit, which is given by: 𝑘 [35], resulting in the complex function:…”

“…This research is similar to Javh et al [12] and takes each pixel as a sensor and then uses the Morlet-wave-modal method [35] to perform the modal identification. In this way the modal parameters are identified directly from the pixel intensities without the need to first retrieve the displacement response, which is due to the fact that, assuming a small displacement, the displacement of the object is linearly related to the change in intensity.…”

Identification of Damping of Spruce Wood (Picea abies) under Various Levels of Moisture Content Using Time-Scale Decomposition

“…Today, the wavelet transform is used to determine various modal parameters. For example, the method can be used to determine the damping [19,[22][23][24], the natural frequencies of oscillations [25][26][27], or the mode shapes [28]. The WT has thus proven to be a very useful and accurate method for determining various modal parameters, whereby it can be used to filter out the influence of environmental disturbances effectively or as a filter for extracting a particular vibration mode [19,23,29].…”