Special Seminar: Ron Miller, 07-Mar-25, 10am
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Ellad Tadmor
Mar 4, 2025, 4:56:18 PMMar 4
to aem-solid...@umn.edu
AEM Mechanics Research Seminar
Friday 07-Mar-2025, 10:00am Central
Prof. Ron Miller
Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, Canada
Title: Polymer nanocomposites for ballistic protection: synthesis, characterization and molecular simulation
Abstract: Nanocomposites and nanostructures often behave in ways that are counterintuitive to our expectations from macroscopic analogues, and we are interested in exploring these behaviours and exploiting them for improved material performance. In particular we have been interested in polymer-based systems, either with a nanoscale filler material or combined with other nanostructured materials, for applications at high strain rate. We have synthesized polyurethane composites with Halloysite nanotubes (HNTs) at less than 1 wt%, and demonstrated that these materials show a 21% increase in fracture toughness and 35% increase in spall strength. More importantly, our characterization and simulation work elucidates the underlying mechanisms of this improvement, and shows that the HNTs are not behaving as a traditional toughening phase in a composite. Rather, they act to favourably modify the microstructure in the surrounding polymer matrix. We also make use of molecular dynamics simulation to understand the ballistic and spall behaviour of polymer and multilayer systems (polymer with metal or ceramic). Our simulations allow us to test some of the common assumptions made in spall experiments and show that at the nanoscale, extremely high ballistic penetration resistance can be observed. Further, some nanoscale multilayers behave completely counter to our expectations. In this presentation, I will try to summarize the promise and limitations of these nanostructured materials, and convey an appreciation for how molecular dynamics can genuinely help us to design better ballistic materials.
For more information, visit the AEM Mechanics Research Seminar website:
Friday 07-Mar-2025, 10:00am Central
In-person: Room 58, Rapson Hall, University of Minnesota
Online: Webinar registration link
Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, Canada
Title: Polymer nanocomposites for ballistic protection: synthesis, characterization and molecular simulation
Abstract: Nanocomposites and nanostructures often behave in ways that are counterintuitive to our expectations from macroscopic analogues, and we are interested in exploring these behaviours and exploiting them for improved material performance. In particular we have been interested in polymer-based systems, either with a nanoscale filler material or combined with other nanostructured materials, for applications at high strain rate. We have synthesized polyurethane composites with Halloysite nanotubes (HNTs) at less than 1 wt%, and demonstrated that these materials show a 21% increase in fracture toughness and 35% increase in spall strength. More importantly, our characterization and simulation work elucidates the underlying mechanisms of this improvement, and shows that the HNTs are not behaving as a traditional toughening phase in a composite. Rather, they act to favourably modify the microstructure in the surrounding polymer matrix. We also make use of molecular dynamics simulation to understand the ballistic and spall behaviour of polymer and multilayer systems (polymer with metal or ceramic). Our simulations allow us to test some of the common assumptions made in spall experiments and show that at the nanoscale, extremely high ballistic penetration resistance can be observed. Further, some nanoscale multilayers behave completely counter to our expectations. In this presentation, I will try to summarize the promise and limitations of these nanostructured materials, and convey an appreciation for how molecular dynamics can genuinely help us to design better ballistic materials.
For more information, visit the AEM Mechanics Research Seminar website:
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Ellad B. Tadmor, Ph.D.
Russell J. Penrose Professor
Department of Aerospace Engineering and Mechanics
University of Minnesota
https://dept.aem.umn.edu/~tadmor/
Russell J. Penrose Professor
Department of Aerospace Engineering and Mechanics
University of Minnesota
https://dept.aem.umn.edu/~tadmor/
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