Drithi Shetty "Improving the Prediction of the Nonlinear Dynamics of Structures"

4:00 pm
March 25, 2024
Room:  190 Goodwin Hall
Drithi Shetty,  Postdoctoral Associate at Rice University

Abstract:  The advancement of aerospace technology demands structures resilient to extreme conditions. These structures are characterized by nonlinear interactions between different physical phenomena that affect global dynamics. For instance, thin composite panels, integral to hypersonic vehicle design, exhibit nonlinear dynamics arising from both material properties and coupled bending-stretching behavior due to large deformations. Moreover, frictional forces at bolted interfaces in aerospace structures further compound these nonlinear effects. Conventional linear analysis fails to capture these complexities, often leading to exhaustive testing or, worse, unexpected structural failures. 

This seminar will detail my latest research on the experimental characterization and numerical analysis of structures exhibiting friction-induced, geometric, or material-based nonlinearity. I will first present the in-situ experimental characterization of elastomeric dampers, such as those used to mitigate off-axis vibrations in turbomachinery. I will show how the dynamic properties of viscoelastic materials are affected by their operating environment in ways not captured by traditional material characterization methods such as dynamic mechanical analysis. I will then present a novel reduced-order model that can predict the dynamics of a structure exhibiting bending-stretching coupling due to large deformations as well as friction due to bolted interfaces. I will also present a new method to measure the amount of contact at an interface using ultrasound, aiding in multiscale modeling of friction. Through these developments, I will show how the interactions between the different sources of nonlinearity affect the overall dynamic behavior of a structure. The insights gained lay the groundwork for future endeavors aimed at accurate and efficient prediction of the dynamics of complex multi-physical structures, propelling us toward safer and more reliable aerospace systems.

Bio:  Drithi Shetty is a postdoctoral associate at Rice University. She received her Ph.D. in Mechanical Engineering from the University of Wisconsin – Madison in 2022. Drithi’s expertise lies in nonlinear dynamics and vibrations, with computational as well as experimental experience. Her recent work includes model reduction techniques, dynamic analysis of viscoelastic materials, and the measurement and analysis of contact evolution. She is a recipient of the 2022 Rice Academy Postdoctoral Fellowship.