Full Content is available to subscribers

Subscribe/Learn More  >

Methods of Determining a Damping Ratio From a Simple Impact Test

[+] Author Affiliations
Cordelia K. Chandler

Framatome ANP, Inc., Lynchburg, VA

Paper No. PVP2005-71041, pp. 359-370; 12 pages
  • ASME 2005 Pressure Vessels and Piping Conference
  • Volume 4: Fluid Structure Interaction
  • Denver, Colorado, USA, July 17–21, 2005
  • Conference Sponsors: Pressure Vessels and Piping Division
  • ISBN: 0-7918-4189-8 | eISBN: 0-7918-3763-7
  • Copyright © 2005 by ASME


Numerous tests have been performed in the nuclear industry to determine damping ratios for the analysis of steam generator tube bundles. Several methods have been used to analyze the response data, including the logarithmic decrement method, the half-power point method, and curve-fitting methods. Theoretically, the methods give the same damping results; however, in practice, the results may be appreciably different. Each of these methods presents certain difficulties in determining a damping ratio. For the half-power point method, the difficulties include selecting a sampling rate, setting a time span, and the use of a window to truncate the data. The difficulties associated with the logarithmic decrement method include selecting the initial and final peaks and selecting an appropriate frequency. In both cases, most of the difficulties arise from the need for subjective decisions by the engineer or technician. Blind curve-fitting methods have been shown to underestimate the actual damping. A practical comparison of these three methods was performed on damping data from a simple impact test. While the half-power point method and curve-fitting methods are useful tools to validate damping results, a logarithmic decrement method that averages the damping over a number of cycles appears to provide the most consistent and realistic damping results for SG tubes.

Copyright © 2005 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In