Quantitative damage detection in cross-ply laminates using Lamb wave method

• Published in: Composites science and technology Vol. 63; no. 10; pp. 1473 - 1479
• Main Authors: Toyama, N., Noda, J., Okabe, T.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2003; Elsevier
• Subjects: A. Polymer matrix-composites (PMCs); Applied sciences; C. Delamination; C. Transverse cracking; D. Non-destructive testing; D. Ultrasonics; Exact sciences and technology; Forms of application and semi-finished materials; Laminates; Polymer industry, paints, wood; Technology of polymers; A. Polymer matrix-composites (PMCs); C. Delamination; D. Ultrasonics; C. Transverse cracking; D. Non-destructive testing; Laminate; Epoxy resin; Cracking; Experimental study; Lamb wave; Non destructive method; Transverse crack; Investigation method; Glass fiber; Delamination; Carbon fiber; Ultrasonic method
• ISSN: 0266-3538; 1879-1050
• DOI: 10.1016/S0266-3538(03)00163-5

This paper investigates the effects of transverse cracking and delamination on the S 0 mode velocity in GFRP and CFRP cross-ply laminates. We found experimentally that both the stiffness and the velocity decreased as the transverse crack density increased. In contrast, the stiffness decreased but the velocity increased as the delamination length increased. We analytically deduced the relationship between the velocity and the crack density from a combination of a shear-lag analysis and the classical plate theory. We also confirmed that the Lamb wave propagated through the 0° layers in the delaminated regions, and formulized the relationship between the velocity and the delamination length. The predicted crack density and delamination length using the measured velocity were in good agreement with the experimental results. This method is simple and promising for structural health monitoring of composite structures.