Home‎ > ‎Research Group‎ > ‎

Ahmet Deniz Usta

Ahmet Usta

Ahmet Deniz Usta

Ph.D. Mechanical Engineering in Progress 
B.S. Mechanical Engineering 2010

Research Background:

My PhD is mainly focused on the experimental branch of tribology. Using our nano-tribometer, I conduct linear reciprocation experiments on a wide range of materials in both pre- and gross-sliding regimes. Currently I am working on characterizing the effect of laser power during pulsed laser micro polishing of metals on their fretting resistance. For this purpose I keep the normal loading conditions in the plastic regime based on the well-known Hertzian contact calculations and work on the evaluation of wear track profiles. This research problem is one where heat transfer and fluid mechanics are effective on the phenomena at the contact level, hence our need to treat this as a multi-physics problem. My future goals in this research include validation of experimental observations through finite element modeling using Abaqus and Comsol, develop a predictive model bridging laser polishing parameters with the desired tribological properties as outcomes.

Contact mechanics of soft materials is an emerging field where there exists much phenomena which cannot be explained using the currently existing models. My future plan is to utilize our nano-tribometer on soft materials such as skin, artificial skin, tissue paper, etc. These are materials for which mechanical characteristics (yielding, elastic modulus, etc.) and physical properties (porosity, humidity, adhesion via existence of natural fluids like sweat, wax) differ radically from those of metals. In this sense I aim to explain why a specific type of tissue paper feels softer than another, and even the meaning of the feeling of softness in terms of tribological properties.