Computing the linear viscoelastic properties of soft gels using an optimally windowed chirp protocol
Name
1805.07987.pdf
Size
5.54 MB
Format
Adobe PDF
Checksum (MD5)
3a11a26f9d71998ea9b7e2ba5a6a2878
Author(s)
Bouzid, Mehdi
Divoux, Thibaut
Del Gado, Emanuela
Keshavarz, Bavand
Geri, Michela
McKinley, Gareth H
Date Issued
July 2018
Journal
Journal of Rheology
Publisher
Society of Rheology
Citation
Bouzid, Mehdi et al. “Computing the Linear Viscoelastic Properties of Soft Gels Using an Optimally Windowed Chirp Protocol.” Journal of Rheology 62, no. 4 (July 2018): 1037–1050 © 2018 The Society of Rheology
Version
Original manuscript
Abstract
We use molecular dynamics simulations to investigate the linear viscoelastic response of a model three-dimensional particulate gel. The numerical simulations are combined with a novel test protocol (the optimally windowed chirp or OWCh), in which a continuous exponentially varying frequency sweep windowed by a tapered cosine function is applied. The mechanical response of the gel is then analyzed in the Fourier domain. We show that (i) OWCh leads to an accurate computation of the full frequency spectrum at a rate significantly faster than with the traditional discrete frequency sweeps, and with a reasonably high signal-to-noise ratio, and (ii) the bulk viscoelastic response of the microscopic model can be described in terms of a simple mesoscopic constitutive model. The simulated gel response is in fact well described by a mechanical model corresponding to a fractional Kelvin-Voigt model with a single Scott-Blair (or springpot) element and a spring in parallel. By varying the viscous damping and the particle mass used in the microscopic simulations over a wide range of values, we demonstrate the existence of a single master curve for the frequency dependence of the viscoelastic response of the gel that is fully predicted by the constitutive model. By developing a fast and robust protocol for evaluating the linear viscoelastic spectrum of these soft solids, we open the path toward novel multiscale insight into the rheological response for such complex materials.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1122/1.5018715
