Ultrasonic methods are an integral part of NDE and SHM and is a major research area for the center. The center has worked at the forefront of developing inspection and monitoring techniques involving bulk waves, guided wave and non-linear ultrasound. The center has expertise in a range of transduction techniques involving piezoelectrics, EMATs and laser generation. The center has exceptionally well equipped laboratories with cutting-edge equipment and capabilities.

Cryoultrasonic NDE

The inspection of complex shaped parts, which may contain multiple internal vanes and present highly curved surfaces, poses a major challenge to conventional NDE techniques. In current industrial practice, these parts are inspected using x-ray CT (XCT) for internal volumetric defects and liquid penetrant inspections (LPI) for surface breaking cracks. However, the sensitivity of XCT rapidly decreases with part size and material mass density, while LPI is ineffective on internal surfaces or in the presence of high surface roughness. Cryoultrasonic NDE is a new technique that uses the remarkable properties of ice to transform a complex object into a simple-shaped solid, which can then be inspected by combining ultrasonic array measurements with advanced imaging methods.

Experimental methods for ultrasonic testing of complex-shaped parts encased in ice

F Simonetti, M Fox, NDT & E International, 103, 1-11, 2019

Cryo-Ultrasonic NDE: Ice–Cold Ultrasonic Waves for the Detection of Damage in Complex-Shaped Engineering Components,

F Simonetti, IL Satow, AJ Brath, KC Wells, J Porter, B Hayes, K Davis, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 65 (4 ) ,638-647, 2019

NDE of Ceramic Matric Composites (CMC) Engine Components

A new breed of ceramic materials formed with Silicon Carbide fibers in a Silicon Carbide matrix (SiC/SiC) which allow jet engine turbines to operate at significantly higher temperatures than those possible with conventional superalloys, thus leading to higher efficiency and lower emissions. The Center works closely with industry to develop the next generation NDE technology specifically tailored to the unique microstructural characteristics of CMCs and aimed at managing the life cycle of CMC components. At a fundamental level we are developing non-contact methods, such as laser ultrasonics, to study damage formation and progression in CMC specimens tested at very high temperatures. At the applied end we design and test inspection solutions for quality control at manufacture and routine maintenance during service.

Noncontact laser ultrasonic inspection of ceramic matrix composites (CMCs)

R Quintero, F Simonetti, P Howard, J Friedl, A Sellinger, NDT & E International 88, 8-16, 2017

NDE of Additively Manufactured Parts

Additive manufacturing offers unparalleled flexibility in the manufacture of complex-geometry engineering components. The Center is engaged with a number of industrial partners and federal agencies to develop ultrasonic NDE methods for the inspection of metallic components produced by selective laser melting (SLM) and electron beam melting (EBM). The focus is on developing sensitive methods for the detection of damage such as porosity in complex-shaped parts.

Monitoring and repair of defects in ultrasonic additive manufacturing

VK Nadimpalli, GM Karthik, GD Janakiram, PB Nagy,International Journal of Advanced Manufacturing Technology, 108, 2020

Seal Fin Inspection using Feature Guided Waves

It is vital that aero engines can be quickly and effectively inspected for damage. Together with industrial project partners, we have developed an ultrasonic technique for defect screening in the seal fins of aero engine disks. The feature guided wave travels around the circumference of the disk and is reflected off defects. The technique avoids the need for costly removal of surface coatings saving time and money during inspections.

A guided wave inspection technique for wedge features

Corcoran J, Leinov E, Jeketo A, Lowe MJS, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 67, 997-1008, 2020

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Non-Destructive Residual Stress Profiling

The Center has world leading expertise in non-destructive residual stress measurement. The center is currently leading an effort to use a multi-modal electromagnetic technique that incorporates eddy-current and Hall coefficient measurements. The approach builds on decades of research experience and has shown very promising results. New analytical methods and experimental methods have been established.

Inversion procedure for dual-mode electromagnetic nondestructive characterization of shot-peened IN718

D Velicheti, PB Nagy, and W Hassan, NDT&E Int. 101, 17-28, 2019.

High-frequency Hall coefficient measurement using inductive sensing for nondestructive materials characterization

D Velicheti, PB Nagy, and W Hassan, NDT&E Int. 94, 109-119, 2018