Software tools for mechanical structures resonant frequencies determination: Vibration signal processing for modal analysis

A LabView virtual instrument is developed to read, process, and save vibration signals. The signal processing realized incudes the Fast Fourier Transform, the corresponding spectrogram visualization, and the spectrogram's peaks localization. These peaks indicate some of the resonant frequencies of the structure investigated. In addition, a Matlab tool with the same vibration signal processing capabilities is developed. It uses the vibration data previously saved with the LabView virtual instrument and is not able to work in real time, but is more functional and has a better results visualization. The LabView virtual instrument is tested with a mechanical plane frame structure and results are compared with theoretically obtained ones. The comparative study is done in the Matlab, based on theoretically obtained data from explicit dynamic finite elements simulations in Abaqus.