@article{35ffbf69c680420f8af0939ee7798c21,
title = "Strain and stress mapping by mechanochemical activation of spiropyran in poly(methyl methacrylate)",
abstract = "The relationship between fracture-induced mechanophore activation and the strain and stress ahead of a propagating crack in poly(methyl methacrylate) (PMMA) is studied. The mechanophore spiropyran is used as a secondary cross-linker in rubber toughened PMMA, and the spiropyran-linked material is subjected to fracture testing. Mechanophore activation is detected and analysed by fluorescence imaging. Digital image correlation is used to measure the strain field ahead of the crack tip, whereas the corresponding stress field is calculated using the Hutchinson–Rice–Rosengren singularity field equations. Mechanophore activation follows a power law dependence on distance from the crack tip and provides both a qualitative and quantitative measure of the strain and stress fields ahead of the crack.",
keywords = "digital image correlation, fracture, spiropyran mechanophore, strain and stress sensors, strain mapping",
author = "Celestine, {Asha Dee N.} and Sottos, {Nancy R.} and White, {Scott R.}",
note = "Funding Information: This work was supported by a MURI grant from the Army Research Office, Grant W911NF-07-1-0409, and a GOALI grant from the National Science Foundation, Grant DMR 13-07354. The Paraloid EXL 2650a rubber nanoparticles were generously provided by Dow Chemicals (Midland, TX, USA). The custom-built experimental set-up was designed and built by Brett Beiermann and Sharlotte Kramer during their time in the Department of Materials Science and Engineering at the University of Illinois. The authors would like to thank Elizabeth Jones for assistance with and meaningful discussions on digital image correlation (DIC). Gratitude is also extended to Professor John Lambros in the Department of Aerospace Engineering at the University of Illinois for the use of his DIC specimen preparation facilities. Funding Information: This work was supported by a MURI grant from the Army Research Office, Grant W911NF‐07‐1‐0409, and a GOALI grant from the National Science Foundation, Grant DMR 13‐07354. The Paraloid EXL 2650a rubber nanoparticles were generously provided by Dow Chemicals (Midland, TX, USA). The custom‐built experimental set‐up was designed and built by Brett Beiermann and Sharlotte Kramer during their time in the Department of Materials Science and Engineering at the University of Illinois. The authors would like to thank Elizabeth Jones for assistance with and meaningful discussions on digital image correlation (DIC). Gratitude is also extended to Professor John Lambros in the Department of Aerospace Engineering at the University of Illinois for the use of his DIC specimen preparation facilities. Funding Information: National Science Foundation, Grant/ Award Number: DMR 13‐07354; Army Research Office, Grant/Award Number: W911NF‐07‐1‐0409 Publisher Copyright: {\textcopyright} 2019 John Wiley & Sons Ltd",
year = "2019",
month = jun,
doi = "10.1111/str.12310",
language = "English (US)",
volume = "55",
journal = "Strain",
issn = "0039-2103",
publisher = "Wiley-Blackwell",
number = "3",
}