Elucidating Microstructural Effects on Elastomer Failure Through Cutting
Wednesday, October 14, 2020
2:30pm – 3:45pm
Virtual via zoom (register by clicking here), Virginia Tech Campus
Mechanical Science and Engineering
University of Illinois Urbana-Champaign
Classic Lake-Thomas theory approximates the energy required to fail polymer networks using bond energy and a microstructural length scale. In unimodal networks, this length scale is taken to be the chain length between crosslinks. Determining a similar length scale can be more challenging in complex networks. Furthermore, emerging experimental evidence and computational prediction suggest that failure occurs in a diffuse manner in a region surrounding the crack tip, as opposed to in a single length scale bridging the crack tip. We apply our recently developed Y-shaped, controlled cutting technique to a series of elastomer networks. At sufficiently small blade radius a plateau in the cutting energy occurs for a range of elastomers having a variety of microstructures. We find that the combination of the plateau cutting energy and length scale at which the plateau occurs scales with a material's toughness, potentially providing insight into tuning the latter behavior.
Shelby Hutchens is an Assistant Professor of Mechanical Science and Engineering at the University of Illinois Urbana-Champaign. Her research interests span from ultrasoft-polymeric-materials characterization to plant-inspired motion. She received all her degrees in Chemical Engineering, Ph.D. and M.S. from Caltech and B.S. from Oklahoma State. She received an NSF CAREER award in 2017.