Structural health monitoring using scanning laser vibrometry: III. Lamb waves for fatigue crack detection

Leong, WH; Staszewski, Wiesław J.; Bc, Lee; Scarpa, Fabrizio

doi:10.1088/0964-1726/14/6/031

Cited by 140 publications

(90 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1,9 The potential for noncontact measurement of the guided waves using a laser vibrometer has been demonstrated for fatigue crack detection in metallic structures. 10,11 Both the excitation and measurement of guided ultrasonic waves can be performed using noncontact laser technology. 12 However, the wavelength of the employed guided waves is usually significantly larger than in bulk wave ultrasonic testing, thus limiting the sensitivity for the detection of small defects.…”

Section: Introductionmentioning

confidence: 99%

Fatigue crack growth monitoring using high-frequency guided waves

Masserey¹,

Fromme

2013

Structural Health Monitoring

View full text Add to dashboard Cite

A common problem in aircraft maintenance is the development of fatigue cracks at fastener holes due to stress concentration. High-frequency guided ultrasonic waves allow for the structural health monitoring of critical areas of a structure and can be measured with high accuracy using a noncontact laser interferometer. The use of a specific type of highfrequency guided ultrasonic wave that has good sensitivity for the detection of small defects, excited using a standard Rayleigh wedge transducer and propagating along the structure, has been investigated. Fatigue crack growth at the side of a fastener hole in a tensile, aluminum specimen was induced by cyclic loading of the structure. The crack length was monitored optically and showed good correlation with fracture mechanics calculations of the expected growth rate. The changes in the guided wave signal due to the fatigue damage were monitored using a noncontact laser interferometer and quantified. The measurements show a good sensitivity for the early detection of fatigue damage and for the monitoring of fatigue crack growth at a fastener hole. The propagation and scattering of the high-frequency guided ultrasonic wave has been simulated numerically using a three-dimensional finite difference code. Good agreement was found between the measured and predicted changes of the ultrasonic signal for the increasing fatigue crack area, allowing in principle for the approximate sizing of the defect.

show abstract

Section: Introductionmentioning

confidence: 99%

Fatigue crack growth monitoring using high-frequency guided waves

Masserey¹,

Fromme

2013

Structural Health Monitoring

View full text Add to dashboard Cite

show abstract

“…One of the earliest set of studies to use scanning laser vibrometry to sense Lamb waves and their interaction with damage was presented in [30][31][32]. In these studies, 1D scanning laser vibrometry was used to measure the out-of-plane velocities of A 0 Lamb wave propagation through aluminium plates with various defects.…”

Section: Lamb Wave Measurement Using 3d Laser Vibrometrymentioning

confidence: 99%

Lamb Wave Interaction with Adhesively Bonded Stiffeners and Disbonds Using 3D Vibrometry

et al. 2016

View full text Add to dashboard Cite

There are many advantages to adhesively bonding stiffeners onto aircraft structures rather than using traditional mechanical fastening methods. However there is a lack of confidence of the structural integrity of adhesively bonded joints over time. Acousto-ultrasonic Lamb waves have shown great potential in structural health monitoring applications in both metallic and composite structures. This paper presents an experimental investigation of the use of acousto-ultrasonic Lamb waves for the monitoring of adhesively bonded joints in metallic structures using 3D scanning laser vibrometry. Two stiffened panels were manufactured, one with an intentional disbonded region. Lamb wave interaction with the healthy and disbonded stiffeners was investigated at three excitation frequencies. A windowed root-mean-squared technique was applied to quantify where Lamb wave energy was reflected, attenuated and transmitted across the structure enabling the size and shape of the defect to be visualised which was verified by traditional ultrasonic inspection techniques.

show abstract

“…By the same means registration can be performed. However it seems that the most information about Lamb wave propagation phenomenon can be achieved using laser scanning vibrometry [7], [8], [9]. This method covers monitored structure with a grid of virtual points at which velocity or displacement is measured.…”

Section: Introductionmentioning

confidence: 99%

Diagnostics using different configurations of sensing networks

Wandowski¹,

Malinowski

Ostachowicz

2011

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Abstract. The aim of this work was the investigation and improvement of a Structural Health Monitoring method. This method was based on guided elastic waves propagation. These waves propagate in thin-walled structures guided by their walls. This particular technique has been considered in the literature as very promising. This research concentrated on diagnostics using attached piezoelectric transducers that excite guided elastic waves. Non-contact method of measurement was used. The laser vibrometer was utilized to measure the velocities of out of plane vibrations related to propagating elastic waves. Excited waves propagate and reflect from the discontinuities encountered on their way, therefore registering them one can obtain information about the structural health of the structure. Several sensor arrangements (networks) were investigated. The focus of the research was on possible area of application and limitations of the investigated networks. Presented research was based on laboratory experiments on prepared specimens. Signals gathered in the discrete network nodes were processed in order to obtain diagnostics information for the whole surface monitored. The voltage signals in the time domain were transferred into spatial domain to indicate the damage position. The signal processing oriented on structural diagnostics was realized in the MATLAB environment.

show abstract

Structural health monitoring using scanning laser vibrometry: III. Lamb waves for fatigue crack detection

Cited by 140 publications

References 25 publications

Fatigue crack growth monitoring using high-frequency guided waves

Fatigue crack growth monitoring using high-frequency guided waves

Lamb Wave Interaction with Adhesively Bonded Stiffeners and Disbonds Using 3D Vibrometry

Diagnostics using different configurations of sensing networks

Contact Info

Product

Resources

About