Dr. Dinakar Sagapuram, assistant professor in the Department of Industrial and Systems Engineering at Texas A&M University, was part of a team whose research was selected for the cover of the September issue of Proceedings of the Royal Society A (PRSA).
The Royal Society is one of the world’s oldest and most preeminent scientific academies. It has published the work of many renowned scientists including Benjamin Franklin’s famous kite experiment, James Chadwick’s detection of the neutron, and Sir Isaac Newton’s Principia Mathematica, which formulated the laws of motion and the action of gravity.
The team’s paper, “Geometric flow control of shear bands by suppression of viscous sliding,” detailed the use of high-speed imaging and micromaker analysis of flow in cutting to deduce the fundamental mechanism of shear band instabilities in metals processing. The research has led to a simple method to better control these instabilities.
“We were interested in not only studying the shear banding problem that affects product quality and machine stability in manufacturing, but also in ways to control the instabilities,” Sagapuram said. “We demonstrated a simple geometric method to suppress shear band formation in machining. It's possible to extend its application to other processes where shear banding can be an issue.”
Sagapuram is collaborating on the work with Koushik Viswanathan (Purdue University), Anirban Mahato (Indian Institute of Technology Patna), Narayan K. Sundaram (Indian Institute of Science), Rachid M’Saoubi (Seco Tools, UK), Kevin P. Trumble (Purdue University) and Srinivasan Chandrasekar (Purdue University).
“There still remain a lot of unanswered questions related to shear bands despite their discovery more than a century ago,” Sagapuram said, “and I will continue to look for new approaches to control these instabilities.”
The picture featured on the cover of the September 2016 issue was taken with a scanning electron microscope and shows the shear band structure of a metal chip formed during cutting.