Graduate student group wins best oral presentation at TMS conference

The presentation, "Local Shock Viscosity Measurement in Composites Using In-situ Time-gated Raman Spectroscopy," was given in mid-March by AAE Ph.D. students Abhijeet Dhiman, Ayotomi Olokun and Nolan Lewis.

A team from the Interfacial Multiphysics Lab won best student oral presentation in the advanced real time imaging category from The Minerals, Metals & Materials Society at the virtual TMS 2021 conference.

The presentation, “Local Shock Viscosity Measurement in Composites Using In-situ Time-gated Raman Spectroscopy,” was given in mid-March by AAE Ph.D. students Abhijeet Dhiman, Ayotomi Olokun and Nolan Lewis. The presentation was based off a paper and work done after the paper, Dhiman said. The work recently was published in the Journal of Dynamic Behavior of Material. Each student is advised by AAE Professor Vikas Tomar.

The research is supported by the Air Force Office of Scientific Research and the Multidisciplinary University Research Initiative award from the Department of Defense. The work aims to the determination of thermo-mechanical behavior from micro-scale features, such as interfaces and phases, in a composite material. The study is performed under shock loading created by the impacts at velocities around 1km/s through a laser-based high-speed impact system developed by Tomar’s research group.

The information on shock stress and temperature is measured in a non-contact manner based on mechanical Raman spectroscopy with nanosecond time resolution. In the study, the group measured the time-domain behavior from polymer bonded composite and quantified shock viscosity in the microscale interfacial domain, Dhiman said. The quantification of shock viscosity provides a measure of energy dissipation from deformation and fracture of material under shock loading, which is used to validate computational models.

“The novelty of the developed technique lies in the fact that the measurement of local behavior provides a real-time analysis of nano/microscale phenomenon in composite materials,” said Dhiman, who received his master’s from AAE in 2018. “This award is a recognition of the hard work and perseverance shown by the team over last year. Our commitment is to provide a lot more contributions to the scientific community using this work.

“I have always guided and motivated myself through the words of Nikola Tesla, who said ‘invention is the most important product of man’s creative brain. The ultimate purpose is the complete mastery of mind over the material world, the harnessing of human nature to human needs.’”