Real-time damage mechanisms assessment in CFRP samples via acoustic emission Lamb wave
modal analysis, Composites 68 317-326.
Numerical simulations were carried out using finite element software ABAQUS to predict the [A.sub.0] Lamb wave
propagation behaviour in a [.sub.4] plate.
The common active SHM methods are Lamb wave
, electromechanical impedance, and active vibration-based methods, the one used in this study .
Observed clues for this mechanism are (1) coupling between the fundamental spheroidal modes of the Earth and atmospheric acoustic modes, (54,168) and (2) the background atmospheric Lamb waves
. (125) Here, atmospheric Lamb wave
propagates non-dispersively in the horizontal direction with a sound velocity of about 310 [ms.sup.-1], while it is balanced hydrostatically in the vertical direction.
The mainly detected modes of AE wave were assumed to S0 and A0 modes of Lamb wave
because the specimen was a thin plate.
Damage detection in composite materials using Lamb wave
In this experiment, the longitudinal wave incidence method was used to excite and accept the ultrasonic Lamb wave
, which was accurate, effective, and easy to excite.
A lamb wave
was excited and its propagation within the structure was inspected to identify damage.
The propagation of Lamb waves
in a structure results in the mode conversion of wave energy into different modes, and the changes in Lamb wave
signals can be used to interrogate structural integrity [25, 26].
Wu and Liu  investigated the measurement of anisotropic elastic constants of fibre-reinforced composite plate by using ultrasonic bulk wave and laser generated Lamb wave
. The group velocity variation of Lamb wave
in Fibre-reinforced composite plate studied by Rhee et al.
BEM has been used in the wave guide of slab; for example, Cho and Rose  analyzed the mode conversion of Lamb wave
at the reflection of boundary by BEM; Zhao and Rose  explored the guided waves on the identification of the size of defect by simulating various size and depth of defects on the slab using BEM.
Kojima, "Detection of delaminations in CFRP laminates by using FBG sensors as lamb wave
receiver," Transactions of the Japan Society for Aeronautical and Space Sciences, vol.