This paper addresses the quantitative assessment of mechanical damping values for long-span bridges from ambient wind and motion data. Using simultaneously recorded wind and acceleration data, the system transfer function can be approximated and more realistic values for damping can be estimated. Data recorded by the Federal Highway Administration for the Deer Island-Sedgwick Bridge in Maine will be used in the present paper to extract mechanical damping values for four vertical modes of vibration. The goal of this analysis is to check the appropriateness of values of mechanical damping currently used in the design of long-span bridges and to seek more realistic estimates for use in future designs. A method for estimating damping using a least-squares fit of the transfer function estimated from the recorded data is used. This technique enables the use of high-resolution spectral estimates to be used in the damping determination.

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  • Accession Number: 00603325
  • Record Type: Publication
  • Files: TRIS, ATRI
  • Created Date: Jan 31 1991 12:00AM