Abstract
Lightweight polymer foam composites are known to dissipate energy under extreme conditions such as severe compressive or impact loading when used as cores in sandwich structures. This is often accompanied with permanent damage or set under excessive deformation. A fundamental question we seek to address is - can we achieve shape recovery without external stimulus after load removal? That is, how do we achieve lightweight and resilient polymer composites?
To that end, our goal is to design and fabricate architected polymer composites with hierarchical cellular structures that undergo substantial deformation accompanied with energy dissipation, and in addition, recover their original geometric configuration after the loading is removed. To achieve this, we apply the concept of periodic negative stiffness associated with snap-through buckling instability achieved by arraying of basic structural elements for facilitating significant deformation beyond the initial peak load and energy dissipation. In addition, pseudo-bistability enables shape recovery of these structures. Fabrication of these hierarchical cellular architectures is enabled by developing additive manufacturing of syntactic foams using powder-based selective laser sintering technique. Overall, in this talk, I will present our research on designing and fabricating polymer composites with hierarchical cellular architecture in view of achieving structural resiliency.
About the Speaker
Pavana Prabhakar is the Charles G. Salmon assistant professor in the departments of Mechanical Engineering and Civil and Environmental Engineering at the University of Wisconsin-Madison, where she leads the Manufacturing and Mechanics Lab (MaMeL). She received her PhD in Aerospace Engineering from the University of Michigan, Ann Arbor in May 2013. Her research interests are in the field of mechanics and advanced manufacturing of architected composite materials, with emphasis on damage and failure in extreme environments. Prabhakar has received numerous awards, including the NSF CAREER, ONR Young Investigator Program, and AFOSR Young Investigator Program Awards. For more information, see http://mamel.engr.wisc.edu
Host: Professor Nikhil Admal and Shelby Hutchens
* Times, dates, and titles are subject to change. Check mechanical.illinois.edu for updated information. This seminar counts toward the requirements for ME 590 and TAM 500.
