Fatigue crack detection in metallic structures with Lamb waves and 3D laser vibrometry

Abstract

The paper presents the application of ultrasonic guided waves for fatigue crack detection in metallic structures. The study involves a simple fatigue test performed to introduce a crack into an aluminium plate. Lamb waves generated by a low-profile, surface-bonded piezoceramic transducer are sensed using a tri-axis, multi-position scanning laser vibrometer. The results demonstrate the potential of laser vibrometry for simple, rapid and robust detection of fatigue cracks in metallic structures. The method could be used in quality inspection and in-service maintenance of metallic structures in aerospace, civil and mechanical engineering industries.

Negative refraction of elastic waves at the deep-subwavelength scale in a single-phase metamaterial

“…The in-plane longitudinal wave will be generated by using piezoelectric lead zirconate titanate (PZT) actuators. The in-plane time-dependent surface velocities are measured on the surface of the plate by a 3D laser scanning vibrometer (Polytec PSV-400-3D) based on the Doppler frequency-shift effect on light waves 33 . Figure 5b shows the schematic of wave beam generation and measurement.…”

Crack Detection using Image Processing for Automobiles and Aircrafts

“…A framework was revealed for distinguishing cracks in a finished aircraft airframe that does not require dismantling of any of the airship components. [17] But if there should arise an occurrence of dismantled parts the quest for break turns out to be all the more simple as every individual segment can be examined for breaks at a speedier pace. So as to securely keep the more established airship in operation, it is important to precisely examine the whole airframe to recognize and repair such cracks before they achieve a level that could imperil the basic capacity of the airframe.…”

High-resolution, High-speed 3-D Dynamically Deformable Shape Measurement Using Digital Fringe Projection Techniques

“…However, because this technique usually measures a point (or small area) per sensor, it is difficult to obtain a large-area response unless a sensor network is used. Area 3-D sensors such as scanning laser vibrometers provide more information (Staszewski, 2007), but because of their low temporal resolution, they are difficult to apply for high-frequency study. Kim et al (2007) noted that using a kilo Hz sensor is sufficient to monitor high-frequency phenomena.…”