System identification from ambient vibration measurements using output-only modal identification techniques

Abstract

Frequency domain decomposition (FDD) method and Random decrement technique are proposed to analyze ambient vibration data. An ambient vibration test was conducted on an 18-story reinforced concrete building, and the proposed methods were applied to estimate modal parameters. The estimated natural frequencies by the FDD method and the RD technique are in good agreement, and comparisons for damping values estimated by the EFDD method and the RD technique show a 72-246 percent difference. The results imply that the proposed methods can accurately evaluate structural dynamic properties from ambient vibration data in a non-destructive manner.