Damping Estimation of Engineering Structures with Ambient Response Measurements

Damping plays a key role in dynamic response prediction, vibration control. Following the brief description of ambient vibration testing and measurements, three nonparametric damping estimation approaches for engineering structures are introduced: (1) time domain approach using Data Correlation (DC); (2) time-frequency analysis via Wavelet Transform (WT), and (3) a spatial domain approach based on Frequency Domain Decomposition (FDD). The major focus of the damping estimation approaches presented is on their capability in dealing with on-site fullscale testing of engineering structures using ambient response measurement. Computer simulations based on ambient response measurements and modal identification of a 15-story office building and a transmission tower were conducted to evaluate their performances of different approaches in dealing with closely spaced modes and noisy data. Major challenges in damping estimation are also discussed.