Determination of loss factor using resonant and non-resonant methods


Birlik G., Turgay S.

1st International Conference on Engineering Computational Technology/4th International Conference on Computational Structures Technology, Edinburgh, Saint Helena, 18 - 21 August 1998, pp.139-146 identifier

  • Publication Type: Conference Paper / Full Text
  • City: Edinburgh
  • Country: Saint Helena
  • Page Numbers: pp.139-146

Abstract

A comparative assessment of resonant, R, and non-resonant, NR, methods is presented. For this purpose two series, B and W series, of cylindrical specimens were prepared and tested in the laboratory. B and W series were assumed to typify respectively low (eta<0.3) and high damping (eta>0.4) materials. Using a dual channel FFT analyzer the specimens were excited either by random or multisine signals in the frequency range, f less than or equal to 200 Hz. Using R and NR methods corresponding loss factors, eta(R) and eta(NR) were obtained for B and W specimens. eta(R) values of the high damping W specimens were similar to 20% high compared to eta(NR) values, in the vicinity of their transition frequencies. eta(R) and eta(NR) values of the low damping B specimens, however, were observed not to differ significantly with respect to each other.