Characterization of Force-Frequency Shifting dynamics for low frequency excitation

Christopher J. Hudson, Rituparna Basu, Martin W. Trethewey, Leonard L. Koss

Research output: Chapter in Book/Report/Conference proceedingConference contribution


A novel approach know as Force Frequency Shifting (FFS) is under developed for low frequency (less that 1 Hz) vibration excitation for large structures (i.e., buildings, bridges, stadiums, ballroom floors, etc.). Initial implementation of the method applied a time variant force to the test structure in a spatially varying fashion. More recent work has demonstrated that low frequency excitation performance gains may be realized through the use of carefully placed stationary components with controllable time-variant damping. This work will present the modeling and subsequent analysis to describe the underlying dynamic phenomena. A system model is developed and numerically solved in Matlab-Simulink. The results show phasing between the stiffness and damping components contribute and inhibit to the desired low frequency excitation force. The damping force is shown to trend toward zero as the difference frequency approaches the natural frequency. A parametric study focusing on the relationship between the time-invariant and time-variant damping demonstrates their effects on the desired low frequency excitation.

Original languageEnglish (US)
Title of host publicationIMAC-XXIV
Subtitle of host publicationConference and Exposition on Structural Dynamics - Looking Forward: Technologies for IMAC
StatePublished - Dec 1 2006
Event24th Conference and Exposition on Structural Dynamics 2006, IMAC-XXIV - St Louis, MI, United States
Duration: Jan 30 2006Feb 2 2006

Publication series

NameConference Proceedings of the Society for Experimental Mechanics Series
ISSN (Print)2191-5644
ISSN (Electronic)2191-5652


Other24th Conference and Exposition on Structural Dynamics 2006, IMAC-XXIV
Country/TerritoryUnited States
CitySt Louis, MI

All Science Journal Classification (ASJC) codes

  • Engineering(all)
  • Computational Mechanics
  • Mechanical Engineering


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