Modelling of Lamb waves for damage detection in metallic structures: Part II. Wave interactions with damage

Abstract

Lamb waves have shown great potential for structural health monitoring. The technique is based on guided ultrasonic waves introduced into a structure at one point and sensed at a different location. Damage in a structure is identified by a change in the output signal. However, previous studies show that even simple structural configurations can lead to complex response signals. Therefore a knowledge and understanding of wave propagation can ease the interpretation of damage detection results. This paper reports an application of the local interaction simulation approach for Lamb wave propagation modelling in metallic structures. The focus of the analysis is on two-dimensional wave interactions with slot-type defects. The method shows the potential for complex modelling of acousto-ultrasonic waves in damage detection applications.

Multiscale Modeling of Advanced Materials for Damage Prediction and Structural Health Monitoring

“…Physics-based computational models play a key role in predicting damage initiation and propagation as a result of mechanical and thermal loading conditions, simulating the interaction of elastic and electromagnetic waves with the predicted damage, and assessing the current condition of the structure. Because of the complexities associated with aerospace materials, in particular fiber-reinforced composites, damage prediction and quantification studies are often limited to two-dimensional (2D) geometries, linearly elastic constitutive models, prescribed damage initiation location and progression path, and ordered microstructures (Murthy and Chamis, 1986;Freund, 1990;Sankar and Marrey, 1997;Lee and Staszewski, 2003;Swaminathan, Ghosh, and Pagano, 2006;Skoček, Zeman, and Šejnoha, 2008). These assumptions can lead to oversimplification of the problem, and therefore, often result in poor prediction of the critical behavior of these materials.…”

A Bayesian methodology for crack identification in structures using strain measurements

“…However, this approach is only effective in dealing with larger defects for the obvious reason that the effects of small flaws on the global vibrational properties are often below the noise level in large structures. Other techniques use changes in the characteristics of ultrasonic waves propagating across existing defects (Giurgiutiou et al, 2001;Lee and Staszewski, 2003;Paget et al, 2003). Ultrasonic approaches, although highly effective in detecting very small defects, require a dense network of sensors that is impractical to implement in larger structures and raises significantly the cost of the equipment.…”

Characterization of sensor performance and durability for structural health monitoring systems

“…A number of key enabling technologies are quickly coming together to provide miniaturized, autonomous, and capable sensing platforms for monitoring the structural integrity and health of a wide variety of civil, industrial, and aerospace systems [1][2][3][4] . Several practical considerations related to optimal sensor placement, efficient data analysis and reduction methods, and understanding the fundamental physics between sensing data and structural damage levels are also being addressed [5][6][7][8] . In the aerospace industry, the implications of SHM and ISHM are expected to be significant and revolutionary with respect to safe-life engineering design, condition-based maintenance, and damage prognosis assessment.…”