The tranmission of guided wave ultrasonic was monitored across the bolted interface to study the effect of bolt tightening on the interfacial contact. The results revealed a direct correlation between bolt torque hence interfacial contact and the wave transmission. This study was further expanded to monitor the progression of corrosion using the wave transmission.

Published in Journal of Engineering Failure Analysis

Weak interfacial contact due to bolt loosening felicitate significant interaction of guided wave and the bolthole. Wave cannot pass through the bolthole due to different acoustic impedance hence scattering happens at the location of bolthole. This hypothesis was tested on bolted specimen showing that there is a correlation between applied bolt torque and the intensity of scattering.

Presented and published in SMAR2019 conference held in Germany

Reflection based bolt torque monitoring study was expanded to develop a novel imaging tool. It was established that scattering pattern near the bolthole location can be correlated with the bolt torque. A time of flight based imaging tool was developed to monitor the bolt torque. This method has the potential to be baseline free and can be automated.

Published in ASME Journal of nondestructive evaluation, diagnostics and prognostics of engineering systems

An imaging based tool was developed to detect cracks in concrete. A numerical model was developed using finite different time domain method. Wave propagation was simulated through elastic wave equations. The scope of ultrasonic wave based imaging was tested on different models.

Presented and published in 11th international conference on structural integrity and failure held in Perth

Class IV laser based health monitoring can felicitate long distance range inspections without the use of any amplifier. Broad spectrum stress wave were used to monitor different stages of corrosion in steel bar usually used in reinforced steel bar in concrete.

Published in conference of Structural Health Monitoring held at University of Stanford

Healing of cracks in concrete through cement grout was established through ultrasonic based NDT method. It was established that wave based techniques can effeciently identify the healing of cracks at different depths in concrete. A numerical model using finite difference time domain method was developed by Dr. Shah to predict and validate the experimental outcomes.

Published in MaterialsToday Communications

Thin cracks in concrete are tough to fill through traditional grout healing. Therefore, we require low viscous fluids to penetrate the cracks. Bacterial solution can settle in the cracks and results in calcification. This Healing has been monitored through pulse transmission technique

Published in Proceedings of the Final Conference of RILEM 253-MCI Microorganisms-Cementitious Materials Interactions Volume II