Structural hierarchies define toughness and defect-tolerance despite simple and mechanically inferior brittle building blocks
Name
Buehler_Structural hierarchies.pdf
Size
6.31 MB
Format
Adobe PDF
Checksum (MD5)
8b043faa5926dc86e577562e86de67c4
Author(s)
Sen, Dipanjan
Buehler, Markus J
Date Issued
July 2011
Journal
Scientific Reports
Publisher
Nature Publishing Group
Citation
Sen, Dipanjan, and Markus J. Buehler. “Structural Hierarchies Define Toughness and Defect-tolerance Despite Simple and Mechanically Inferior Brittle Building Blocks.” Scientific Reports 1 (2011).
Version
Author's final manuscript
Abstract
Mineralized biological materials such as bone, sea sponges or diatoms provide load-bearing and armor functions and universally feature structural hierarchies from nano to macro. Here we report a systematic investigation of the effect of hierarchical structures on toughness and defect-tolerance based on a single and mechanically inferior brittle base material, silica, using a bottom-up approach rooted in atomistic modeling. Our analysis reveals drastic changes in the material crack-propagation resistance (R-curve) solely due to the introduction of hierarchical structures that also result in a vastly increased toughness and defect-tolerance, enabling stable crack propagation over an extensive range of crack sizes. Over a range of up to four hierarchy levels, we find an exponential increase in the defect-tolerance approaching hundred micrometers without introducing additional mechanisms or materials. This presents a significant departure from the defect-tolerance of the base material, silica, which is brittle and highly sensitive even to extremely small nanometer-scale defects.
MIT Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Massachusetts Institute of Technology. Laboratory for Atomistic and Molecular Mechanics
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike 3.0
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1038/srep00035
