The implementation of structural health monitoring systems in modern aircraft structures made of carbon fibre reinforced plastics requires a deeper understanding of the propagation of impact generated Lamb waves. In this paper a digital shearing interferometry method is presented that allows visualization of laser generated Lamb waves. The contactless full field measurement of these waves is pe...

In the present work, the interaction of Rayleigh waves with a delamination in a fiber reinforced composite plate was analyzed. Rayleigh waves, upon interacting with delamination mode, convert into Lamb waves in the delamination zone. These guided Lamb modes have the capability to mode convert back into Rayleigh modes when they interact with the edge of the delamination. A unidirectional glass/e...

Lamb waves are often used in ultrasonic applications for non-destructive testing of large constructions. The difficulty in the analysis of Lamb waves is their dispersive characteristics, especially their frequency dependent phase and group velocities. This article focuses on the separation of the first symmetric mode S0 and the first asymmetric mode A0 and the reliable estimation of their group...

Corrosion is detrimental to the structural integrity of many critical components, and ultrasonic methods are routinely used in the field to make thickness measurements at points of interest. However, is often difficult to assess the true extent of corrosion damage because of the likelihood of missing small corroded areas and the difficulty in mapping the extent of large corroded areas without a...

Introduction Compared to ultrasonic bulk waves that travel in infinite media with no boundary influence, guided waves require a structural boundary for propagation. As an example, some guided wave possibilities are illustrated in Figure 1 for a Rayleigh surface wave, a Lamb wave, and a Stonely wave at an interface between two materials.

Ultrasonic guided wave inspection is much more efficient than traditional point-bypoint examination. Guided waves can propagate over long distances from a single position, and therefore is a good method of evaluating thickness degradation, especially for large-area structures such as pipes and vessels. In this paper, guided wave thickness measurement potential is studied utilizing a peak freque...

Research into ultrasonic guided wave non-destructive testing for the long range inspection of large metallic structures is now well advanced. The main advantage of this method is that a large area can be covered from a given transducer position, so avoiding expensive scanning of all the structure surface. However, in the presence of attenuative coatings the test range can be dramatically reduce...

BACKGROUND Ultrasound induces mechanical vibration and heat, causing differentiation and proliferation in osteoblasts. All known in vitro evaluations of ultrasound are, however, performed with longitudinal ultrasound waves. We addressed a question: Do other forms of ultrasound waves, such as guided waves (longitudinal and guided flexural) transduced at a remote location, enhance differentiation...