Real-time nondestructive evaluation of fiber composite laminates using low-frequency Lamb waves
- 1 May 2002
- journal article
- Published by Acoustical Society of America (ASA) in The Journal of the Acoustical Society of America
- Vol. 111 (5), 2026-2033
- https://doi.org/10.1121/1.1466870
Abstract
Amid the nondestructive evaluation techniques available for the inspection of composite materials, only a few are suitable for implementation while the component is in service. The investigation examines the application of Lamb waves at low-frequency-thickness products for the detection of delaminations in thick composite laminates. Surface-mounted piezoelectric devices were excited with a tone burst to generate elastic waves in the structure. Experiments were carried out on composite beam specimens where wave propagation distances over 2 m were achieved and artificially induced delaminations as small as 1 cm2 were successfully identified. The feasibility of employing piezoelectric devices for the development of smart structures, where a small and lightweight transducer system design is required, has been demonstrated. The resonance spectrum method, which is based on the study of spectra obtained by forced mechanical resonance of samples using sine-sweep excitation, has been proposed as a technique for measuring the A0 Lamb mode phase velocity. The finite-element method was also used to investigate qualitatively the dynamic response of laminates to wave propagation. Several locations and spatial distribution of the actuators were examined showing the advantages of using transducers arrays for the inspection of large structures.Keywords
This publication has 8 references indexed in Scilit:
- DELAMINATION DETECTION IN COMPOSITE LAMINATES FROM VARIATIONS OF THEIR MODAL CHARACTERISTICSJournal of Sound and Vibration, 1999
- Flexible interdigital PVDF transducers for the generation of Lamb waves in structuresUltrasonics, 1997
- Broadband Lamb wave measurements in aluminium and carbon/glass fibre reinforced composite materials using non-contacting laser generation and detectionUltrasonics, 1997
- Hertzian contact transducers for nondestructive evaluationThe Journal of the Acoustical Society of America, 1996
- Amplitude spectrum method for the measurement of phase velocityUltrasonics, 1989
- Low Frequency Flexural Wave Propagation in Laminated Composite PlatesPublished by Springer Science and Business Media LLC ,1988
- Practical application of the rapid frequency sweep technique for structural frequency response measurementThe Aeronautical Journal, 1982
- On the determination of phase and group velocities of dispersive waves in solidsJournal of Applied Physics, 1978