Ultrasonic guided waves based non-destructive testing (NDT) is attractive due to its potential for long range inspection. In NDT, fiber Bragg gratings (FBG) sensor is widely adopted due to its rugged wavelength encoded information and immunity to electromagnetic interference (EMI). In this paper we discuss the reception of ultrasonic guided waves in a glass fiber reinforced plastic (GFRP) composite plate using a surface bonded FBG sensor. Experimentally deduced values for wave velocity and attenuation are compared with the theoretical values. © 2018 IEEE.

Prabhu Rajagopal

Department of Mechanical Engineering

Balaji Srinivasan

Department of Electrical Engineering

Electromagnetic pulse

Fiber Bragg gratings

Fiber reinforced plastics

Guided electromagnetic wave propagation

Nondestructive examination

Ultrasonic waves

Composite plates

ENCODED INFORMATION

FIBER BRAGG GRATINGS SENSORS

LONG RANGE INSPECTION

Non destructive testing

Theoretical values

ultrasonic guided wave

Wave velocity

Ultrasonic testing

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Detection of Guided Waves in a Composite Plate Using Surface Bonded Fiber Bragg Gratings Sensor

Proceedings of IEEE Sensors

Aerospace & Automotive industries make extensive use of composite structures, often with complex geometries. Ultrasonic guided waves are attractive for long-range inspection of large-scale structures. However surface based transducers that are typically used, lead to two-dimensional wave propagation, limiting the applicability of guided wave methods. This work explores the use of embedded waveguides for monitoring delamination type defects in composites. These waveguides confine the wave transmission in one dimension and waves leak only through the opening provided, which enhances the capability to inspect large composite structures with very low attenuation rate. Inaccessible areas can be inspected and inter-laminar delamination detection can be achieved. Live monitoring and assessment of discontinuities can be accomplished effectively by using this mechanism. © 2017 Author(s).

Fulltext

AIP Conference Proceedings

Guided waves for online monitoring of composites

Harnessing of ultrasonic guided waves confined in local features such as bends and welds, known as feature-guided waves, has emerged as a promising technique for non-destructive testing and structural health monitoring of industrial and aerospace structures. This article introduces a fiber Bragg grating based technique which uses feature-guided waves to detect anomalies or defects in plate structures with transverse bends. We are able to obtain good consistency between simulation and experimental results, both in the case of defect-free bent plates and those with transverse defects. Such results establish fiber Bragg gratings as a viable alternative to conventional techniques for structural health monitoring of bent plates. © 2016, © The Author(s) 2016.

Journal of Intelligent Material Systems and Structures

Feature-guided wave-based health monitoring of bent plates using fiber Bragg gratings

Shear horizontal guided waves are attractive for structural health monitoring applications in view of the non-dispersive behaviour of the fundamental mode, possibly higher frequencies of operation and a less complex multi-modal structure. One of the key issues with the deployment of shear horizontal guided waves of modes for structural health monitoring applications is the general non-availability of techniques to sense this family of modes effectively. This article demonstrates the detection of fundamental shear horizontal waves in an aluminium plate by placing a fibre Bragg grating along a direction perpendicular to that of propagating guided elastic waves. In order to uniquely identify the three fundamental plate-guided modes, we map the experimentally measured group velocities as detected by the fibre Bragg grating to theoretically obtained group velocity dispersion curves. We find that the experimentally measured group velocity values using time-of-flight measurements from a perpendicularly placed fibre Bragg grating are in agreement with the theoretical curve for the S H 0 mode. Possible extension of these results to feature-guided modes is also discussed. © The Author(s) 2016.

Detection of fundamental shear horizontal mode in plates using fibre Bragg gratings

Monitoring of Delamination Growth in CFRP Laminates using Chirped FBG Sensors

In situ Strain and Temperature Monitoring of Adaptive Composite Materials

Journal	Data powered by TypesetProceedings of IEEE Sensors
Publisher	Data powered by TypesetInstitute of Electrical and Electronics Engineers Inc.
ISSN	19300395
Open Access	No