Development of fiber optic acoustic emission sensors

Finkel, Peter; Miller, R.W.; Finlayson, Richard D.; Borinski, Jason W.

doi:10.1063/1.1373977

Cited by 7 publications

(6 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A fiber-optic (FO) sensor [2] tuned to the 200-kHz frequency range was attached to the structure about 50 mm from the defect using solid bond agent (Salol). As mentioned before, the presence of an external magnetic field normal to the defect plane field increases the Lorentz stresses at the crack tips.…”

Section: Methodsmentioning

confidence: 99%

“…I T was shown by Finkel et al [1], [2] that it is possible to use electromagnetic stimulation to produce acoustic emission (AE) signals used to locate small flaws or cracks in thin-walled structures nondestructively to allow inspection of specific areas without loading the whole structure. Reliable and accurate flaw detection and sizing is critical in ensuring the structural integrity of the airframe structures.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electromagnetic Stimulation of the Ultrasonic Signal for Nondestructive Detection of Ferromagnetic Inclusions and Flaws

Finkel¹,

Godinez²

2004

IEEE Trans. Magn.

View full text Add to dashboard Cite

In this paper, the method of nondestructive detection based on electromagnetic modulation of the ultrasonic signal scattered from the inclusions or defects has been reported. The electromagnetically induced high-density current pulse generates transient stress fields which alter the ultrasonic waves scanning the part with the defect and modulate the ultrasonic signal due to magnetoelastic coupling, magnetostriction, or the "crack closure" effect. The results of applying electromagnetic transient modulation of the ultrasonic echo pulse tone-burst suggest that this method could be used to enhance detection of small cracks and ferromagnetic inclusions in thin-walled metallic structures.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electromagnetic Stimulation of the Ultrasonic Signal for Nondestructive Detection of Ferromagnetic Inclusions and Flaws

Finkel¹,

Godinez²

2004

IEEE Trans. Magn.

View full text Add to dashboard Cite

show abstract

“…The magnetic vector potential for each unit cell is calculated according to Equation (2), where the function f (z, z o , a) is listed in Equations ( 10) and ( 11) for the meandering and additive coil designs, respectively. A solution is formed by applying the principle of linear superposition and summing all of the unit cell solutions over the length of z of interest for a given coil layout according to Equation (5). Finally the eddy current density, J(r,z), in the joint layer is found according to Equation (13).…”

Section: Sensor Design Considerationsmentioning

confidence: 99%

“…A nonextensive list of structural health monitoring (SHM) systems to detect cracks includes acoustic emission, 4,5 ultrasonic wedges, 6 pitch-catch acousto-ultrasonic systems using piezo transducers, 7,8 phased array ultrasonic systems using piezo transducers, 9 and electrochemical sensors. 10 Such surface-mounted sensor systems can monitor the layer on which they are bonded and perhaps the underlying layer for cracks.…”

Section: Introductionmentioning

confidence: 99%

A structural health monitoring fastener for tracking fatigue crack growth in bolted metallic joints

Rakow

Chang

2011

Structural Health Monitoring

View full text Add to dashboard Cite

In this study, a structural health monitoring (SHM) fastener consisting of a conformable eddy current sensor film that is integrated with a metallic sleeve that goes around the fastener shank was developed for in situ monitoring of fatigue cracks at hole locations in layered metallic joints. Integration of sensors with the fastener shank is an optimal methodology for embedding sensors to detect cracks, which most commonly initiate at bolt-hole boundaries in metallic airframe components. The sensors are located in proximity to the bolt-hole boundary through the entire joint stack up, enabling detection of cracks on inner joint layers, which are otherwise inaccessible and cannot be detected with traditional surface-mounted SHM technologies. An additive, interleaved, multilayered, electromagnetic (AIME) sensor was designed for this application. The sensor's salient qualities are an enhanced capability to inspect adjacent joint layers with high degrees of liftoff, or separation between sensor and joint layer, and a capability to track cracks out to great depth as they propagate from a through-hole boundary. The analysis and design of the sensor film and sensor/fastener system are presented herein followed by an experimental validation of the complete SHM system.

show abstract

“…A number of fiber optic acoustic emission sensors suitable for these applications have been developed in the past 30 years. The majority of these sensors, such as the Mach-Zahnder [ 5 , 6 ], Michelson [ 7 ], Sagnac [ 8 ], or Fabry-Perot [ 9 , 10 ] detectors, are based on fiber optic interferometry. These sensors have considerable advantages over conventional piezoelectric sensors, such as immunity to electromagnetic interference and feasibility for long-term and long-distance structural condition monitoring, but they are pretty large in size and are difficult to multiplex.…”

Section: Introductionmentioning

confidence: 99%

Acoustic Emission Source Location Using a Distributed Feedback Fiber Laser Rosette

Huang

Zhang

2013

Sensors

View full text Add to dashboard Cite

This paper proposes an approach for acoustic emission (AE) source localization in a large marble stone using distributed feedback (DFB) fiber lasers. The aim of this study is to detect damage in structures such as those found in civil applications. The directional sensitivity of DFB fiber laser is investigated by calculating location coefficient using a method of digital signal analysis. In this, autocorrelation is used to extract the location coefficient from the periodic AE signal and wavelet packet energy is calculated to get the location coefficient of a burst AE source. Normalization is processed to eliminate the influence of distance and intensity of AE source. Then a new location algorithm based on the location coefficient is presented and tested to determine the location of AE source using a Delta (Δ) DFB fiber laser rosette configuration. The advantage of the proposed algorithm over the traditional methods based on fiber Bragg Grating (FBG) include the capability of: having higher strain resolution for AE detection and taking into account two different types of AE source for location.

show abstract

Development of fiber optic acoustic emission sensors

Cited by 7 publications

References 2 publications

Electromagnetic Stimulation of the Ultrasonic Signal for Nondestructive Detection of Ferromagnetic Inclusions and Flaws

Electromagnetic Stimulation of the Ultrasonic Signal for Nondestructive Detection of Ferromagnetic Inclusions and Flaws

A structural health monitoring fastener for tracking fatigue crack growth in bolted metallic joints

Acoustic Emission Source Location Using a Distributed Feedback Fiber Laser Rosette

Contact Info

Product

Resources

About