Monitoring dynamic behavior of bridges through wavelet transform of laser doppler vibrometer signal

Monitoring the dynamic behavior of a bridge to evaluate its stability is one of the important maintenance tasks, and it was monitored through the attached sensing previously. This paper presents a study of monitoring the dynamic behavior of a bridge using LDV (Laser Doppler Vibrometer). To determine the natural frequency and displacement of a bridge, the vibrometer has been tested through a calibration of the device at certain specified and controlled conditions of vibration to monitor the accuracy of measuring the LDV, then it was deployed for different types of bridges under different parameters and excitation methods, then measured the vibrations at certain frequencies, lastly compare the measured results and analyze them. The analysis showed the difference in measuring capability of the device at tinies vibration capability, limitations and challenges when using them. As well as the importance and capability of newly developed LDV in the field of engineering generally, and dynamic properties and behaviors of structures specifically. Lastly, the research shows the results from LDV, to be able to use them in other possible structures such as shear walls, columns and retaining walls during different types of dynamic load to monitor overall and specific elements of the structure under various exposures.