Paper Title:
Group Velocity of Lamb Wave S0 Mode in Laminated Unidirectional CFRP Plates
  Abstract

The elastic waves in the isotropic plate are dispersive waves with the characteristics of Lamb wave, however, S0 symmetric mode is less dispersive in the frequency region less than the first cut-off frequency. In the anisotropic plates such as CFRP plates, the propagation velocities vary with the directions as well as the dispersion of the Lamb wave, and the phase velocity direction does not accord with the group velocity direction. The phase velocity direction is equivalent the wave vector direction, while the group velocity direction is equivalent the energy flow direction. In this work, the group velocity dispersion curves were obtained by the dispersion relation of the Lamb wave in unidirectional CFRP plate with an orthotropic structure. The group velocities of the S0 symmetric mode in the frequency region less than the first cut-off frequency were corrected by applying the slowness surface. The propagation velocities of Lamb wave were decided by measuring the arrival time of the Lamb wave signals received with the two pinducers varying the propagating direction in the laminated unidirectional CFRP plates of 8, 16 and 24 plies having a volume fraction of 67%. The measured velocities are better agreement with corrected group velocity curve, except near the fiber direction at the cusp region. When the propagating direction is not accorded with the principal axis, the direction of the group velocities inclines toward the fiber direction in the unidirectional CFRP plates, suggesting that the energy propagates preferentially toward fiber direction.

  Info
Periodical
Key Engineering Materials (Volumes 297-300)
Edited by
Young-Jin Kim, Dong-Ho Bae and Yun-Jae Kim
Pages
2213-2218
DOI
10.4028/www.scientific.net/KEM.297-300.2213
Citation
J. K. Lee, Y. H. Kim, H. C. Kim, "Group Velocity of Lamb Wave S0 Mode in Laminated Unidirectional CFRP Plates ", Key Engineering Materials, Vols. 297-300, pp. 2213-2218, 2005
Online since
November 2005
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Hironori Seki, Masakazu Tane, Hideo Nakajima
Abstract:We studied the fatigue strength of lotus-type porous magnesium with cylindrical pores aligned unidirectionally, which was fabricated through...
1681
Authors: Chang Shun Zhu, Guo Lin Wang, Ping Ping Li, Shang Wei Chen
Abstract:Three-dimensional crack propagating path of tire bead rubber was the premise to study the crack propagation direction of bead. For this...
628
Authors: Takashi Yokoyama
Chapter 5: Dynamic Behaviour of Materials
Abstract:The impact compressive failure behavior of a unidirectional T700/2521 carbon/epoxy laminated composite in three principal material directions...
799
Authors: Chen Bo Ma, Jian Jun Sun, Hua Zhu, Jian Quan Li, Fei Zhou
Chapter 3: Material Science, Technology and Processing
Abstract:To investigate the influence of different direction angles on groove textured surface, tribology experiments for smooth surface and groove...
404