Effect of Rivet Rows on Propagation of Lamb Waves in Mechanically Fastened Two-Layer Aluminum Plates

  • Keun J. Sun
  • Patrick H. Johnston
Chapter

Abstract

Feasibility of using Lamb waves for disbonds and corrosion detections in aircraft fuselage structures was investigated in recent years. Measurement performed on various laboratory-fabricated specimens as well as on panels removed from aircrafts has shown consistent results and demonstrated its potential applications for large area structural integrity evaluation [1–3]. It has been observed that structural flaws existing on the path of Lamb waves not only changed amplitude of waves but also affected their velocities as well. Amplitude change caused by a disbond of size less than 0.5 in. × 0.5 in. was significant and has been measured. Variation in phase velocity was used to quantify the corrosion-induced thickness reduction in aluminum sheets. An area of size 1 in. × 1 in. with 8% thickness loss in subsurface of an 1 mm thick aluminum plate was detected by monitoring the phase velocity increase of SO mode. While these tests made major progresses toward developing a practical and low cost flaw assessment system, effects due to the presence of certain structural elements, such as coatings and fasteners, on the propagation of Lamb waves are becoming important issues, and need to be analyzed. These effects are themselves interesting physical phenomenon and worth investigation, however, it is hoped that propagation variations of waves induced by structural defects can be separated from these effects and be quantitatively correlated to the physical properties of defects.

Keywords

Acoustics Aircrafts 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    K.J. Sun and P.H. Johnston, IEEE 1992 Ultrasonics Symposium Proceedings, 763 (1992).Google Scholar
  2. 2.
    K.J. Sun and P.H. Johnston, in Review of Progress in Quantitative Nondestructive Evaluation, vol. XIII, eds. D.O. Thompson and D.E. Chimenti, 1507 (Plenum Press, New York, 1994).Google Scholar
  3. 3.
    K.J. Sun, D. Kishoni, and P.H. Johnston, IEEE 1993 Ultrasonics Symposium Proceedings 733 (1994).Google Scholar
  4. 4.
    J.S. Heyman and E.J. Chern, Journal of Testing and Evaluation, vol. 10, No. 5, 202 (1982).CrossRefGoogle Scholar
  5. 5.
    D.C. Worlton, J. Appl. Phys., 32, 967 (1961).CrossRefGoogle Scholar
  6. 6.
    T.R. Meeker, and A.H. Meitzler, in Physical Acoustics, vol. I, part A, 111, edited by R.N. Thurston (Academic Press, Inc. 1964).Google Scholar

Copyright information

© Plenum Press, New York 1995

Authors and Affiliations

  • Keun J. Sun
    • 1
  • Patrick H. Johnston
    • 2
  1. 1.Applied Science, Department of PhysicsCollege of William and MaryWilliamsburgUSA
  2. 2.NASA-Langley Research CenterHamptonUSA

Personalised recommendations