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Free Vibration Analysis of Pyroshock-Loaded Hardened Structures

  • Jason R. Foley
  • Lashaun M. Watkins
  • Brian W. Plunkett
  • Janet C. Wolfson
  • Preston C. Gillespie
  • Jeffrey C. Van Karsen
  • Alain L. Beliveau
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

The free vibration response of a high stiffness, high strength (hardened) structural member is characterized under a variety of energetic and simulated pyroshock system inputs. The hardened structure studied is a structural pipe which includes a reinforcing material, e.g., a composite potting, with threaded end caps. Impulsive loads are imparted on the structure using bulk explosives and non-energetic impacts. The free vibration response of the structure is measured using a variety of sensors (accelerometers and strain gages); the observed experimental modes are compared with computationally estimated and experimentally observed principle modes up to approximately 5 kHz. The operating (output-only) response of the system is also compared to show the effects of damaged reinforcing materials on the vibration frequencies and observed damping. The operating mode shapes also exhibit nonlinearities which are discussed, with possible explanations including rate- and amplitude-dependent damping.

Keywords

Mode Shape Free Vibration Vibration Analysis Structural Member System Input 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Harris, C.M., and Piersol, A.G., 2002, Shock and Vibration Handbook, 5th Edition, McGraw-Hill, New York.Google Scholar
  2. 2.
    Powers, D., ”Summary of Testing Techniques,“ Shock and Vibration Bulletin, 1986, Vol. 56, pp. 135–142.Google Scholar
  3. 3.
    Keon, S.P., ”Pyrotechnic Shock Testing: Real Test Lab Experiences at EBA&D,“ 2006.Google Scholar
  4. 4.
    Bai, M., and Thatcher, W., ”High G Pyrotechnic Shock Simulation Using Metal-to-Metal Impact,“ Shock and Vibration Bulletin, 1979, Vol. 49, pp. 96–100.Google Scholar
  5. 5.
    Davie, N., ”The Controlled Response of Resonating Fixtures Used to Simulate Pyroshock Environments,“ Shock and Vibration Bulletin, 1986, Vol. 56, pp. 119–124.Google Scholar
  6. 6.
    Parry, D.J., et al., ”Hopkinson bar pulse smoothing,“ Measurement Science and Technology, 1995, Vol. 6, No. 5, pp. 443–446.MathSciNetCrossRefGoogle Scholar
  7. 7.
    Inman, D.J., 2008, Engineering Vibration, Pearson, Upper Saddle River, pp. 485–487.Google Scholar
  8. 8.
    Johnson, G.R., et al., 1987, ”User Instructions for the EPIC-3 Code,“ available from AFATL-TR-86-51.Google Scholar
  9. 9.
    2009, LS-DYNA User’s Manual, LSTC.Google Scholar
  10. 10.
    Idesman, A.V., et al., ”A new explicit predictor-multicorrector high-order accurate method for linear elastodynamics,“ Journal of Sound and Vibration, 2008, Vol. 310, No. 1–2, pp. 217–229.CrossRefGoogle Scholar
  11. 11.
    2005, ”Model 7270A Accelerometer Data Sheet,“ Endevco Corporation.Google Scholar

Copyright information

© Springer Science+Businees Media, LLC 2011

Authors and Affiliations

  • Jason R. Foley
    • 1
  • Lashaun M. Watkins
    • 1
  • Brian W. Plunkett
    • 1
  • Janet C. Wolfson
    • 1
  • Preston C. Gillespie
    • 2
  • Jeffrey C. Van Karsen
    • 3
  • Alain L. Beliveau
    • 4
  1. 1.Air Force Research LaboratoryAFRL/RWMFEglin AFBUSA
  2. 2.Jacobs Engineering, Inc.New yorkUSA
  3. 3.LMS Americas, Inc.EllicottAmerica
  4. 4.Applied Research Associates, Inc.AlbuquerqueUSA

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