NEHRP Clearinghouse
- Title
- Damping Measurements of Tall Structures.
- File
- PB82147836.pdf
- Author(s)
- Taoka, G. T.
- Source
- National Science Foundation, Washington, DC. Engineering and Applied Science., January 1980, 18 p.
- Abstract
- Results of an investigation of damping measurements of five tall steel structures are presented. The structures include four buildings ranging in height from 103 to 170 meters, and a four-legged square tower of a total height of 333 meters. For each structure, ambient vibration records were mechanically digitized and analyzed by three system identification methods: the correlation method, the spectral moments method, and the power spectral density method. A trapezoidal filter was used to isolate individual modes before the records were subjected to analysis. Damping estimates were also obtained under forced vibration rotating shaker tests. These estimates appeared to be consistent with those obtained under ambient conditions for fundamental modes of vibration. Considerable variations were present when damping ratios for higher mode estimates were compared.
- Keywords
- Skyscrapers; Earthquake resistant structures; Steel structures; Spectral energy distribution; Forced vibration; Dynamic response; Earthquake engineering; Random vibration; Vibration damping