Share Email Print
cover

Proceedings Paper

Experimental study of Lamb wave propagation in composite laminates
Author(s): Lei Wang; F. G. Yuan
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

This paper focuses on the existence of higher-order Lamb wave modes that can be observed from piezoelectric sensors by the excitation of ultrasonic frequencies from piezoelectric actuators. Using three-dimensional (3-D) elasticity theory, the exact dispersion relations governed by transcendental equations are numerically solved for an infinite number of possible wave modes. For symmetric laminates, a robust method by imposing boundary conditions on mid-plane and top surface is developed to separate wave modes. Then both phase and group velocity dispersions of Lamb waves in composites are obtained. Meanwhile three characteristic wave curves including velocity, slowness, and wave curves are introduced to analyze the angular dependency of Lamb wave propagation at a given frequency. In the experiments, two surface-mounted piezoelectric actuators are operated corporately to excite either symmetric or anti-symmetric wave modes with narrow banded excitation signals, and a Gabor wavelet transform is used to extract group velocities from arrival times of Lamb wave received by a piezoelectric sensor. In comparison with the results from the theory and experiment, it is confirmed that the higher-order Lamb waves can be excited from piezoelectric actuators and the measured group velocities agree well with those from 3-D elasticity theory.

Paper Details

Date Published: 11 April 2006
PDF: 12 pages
Proc. SPIE 6174, Smart Structures and Materials 2006: Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems, 617442 (11 April 2006); doi: 10.1117/12.677936
Show Author Affiliations
Lei Wang, North Carolina State Univ. (United States)
F. G. Yuan, North Carolina State Univ. (United States)


Published in SPIE Proceedings Vol. 6174:
Smart Structures and Materials 2006: Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems
Masayoshi Tomizuka; Chung-Bang Yun; Victor Giurgiutiu, Editor(s)

© SPIE. Terms of Use
Back to Top