Medium-amplitude oscillatory shear (MAOS) is asymptotically nonlinear and a valuable tool for inferring structure from rheology. However, a drawback of conventional MAOS is the time and material intensive nature of experiments. Many strain amplitude sweeps, and typically multiple sample loadings, are required to obtain frequency-dependent properties. Here, we propose a new MAOS methodology that is much faster (fewer data points) and cheaper (fewer material loadings): The frequency-sweep MAOS. Similar to conventional frequency-sweep SAOS (small-amplitude oscillatory shear), we use only a frequency-sweep. A key challenge is that measurable MAOS data lie within a narrow and frequency-dependent domain between the instrument resolution (at small strain amplitudes) and nonlinear behavior beyond asymptotic nonlinearity (at large strain amplitudes). This necessitates a nonconstant strain amplitude γ0(ω) for the frequency-sweep instead of a single constant strain amplitude. We provide guidelines for finding this γ0(ω) trajectory for frequency-sweep MAOS. Full characterization of all four MAOS measures requires two frequency-sweeps: One frequency-sweep for the third-harmonic measures and two frequency-sweeps (at different input strain amplitudes) for the first-harmonic measures. We propose criteria to validate this MAOS data taken at a single strain amplitude based on ratios of stress harmonics; a similar idea is extended to validate frequency-sweep SAOS data as well. The proposed method of frequency-sweep MAOS is demonstrated for a polyvinyl alcohol-borax hydrogel. This new, faster, and material economical MAOS approach will be particularly beneficial for precious samples with very limited availability such as model polymers with well-defined architectures.
Skip Nav Destination
Article navigation
January 2018
Research Article|
January 01 2018
Frequency-sweep medium-amplitude oscillatory shear (MAOS)
Piyush K. Singh;
Piyush K. Singh
Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign
, Urbana, Illinois 61801
Search for other works by this author on:
Johannes M. Soulages;
Johannes M. Soulages
Corporate Strategic Research, ExxonMobil Research and Engineering
, Annandale, New Jersey 08801
Search for other works by this author on:
Randy H. Ewoldt
Randy H. Ewoldt
a)
Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign
, Urbana, Illinois 61801
Search for other works by this author on:
a)
Author to whom correspondence should be addressed; electronic mail: [email protected]
J. Rheol. 62, 277–293 (2018)
Article history
Received:
August 10 2017
Accepted:
October 30 2017
Citation
Piyush K. Singh, Johannes M. Soulages, Randy H. Ewoldt; Frequency-sweep medium-amplitude oscillatory shear (MAOS). J. Rheol. 1 January 2018; 62 (1): 277–293. https://doi.org/10.1122/1.4999795
Download citation file:
Pay-Per-View Access
$40.00
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Citing articles via
Rheo-SINDy: Finding a constitutive model from rheological data for complex fluids using sparse identification for nonlinear dynamics
Takeshi Sato, Souta Miyamoto, et al.
REVIEW: Nonlinear shear rheometry: Brief history, recent progress, and challenges
Salvatore Costanzo, Daniele Parisi, et al.
Composite entanglement topology and extensional rheology of symmetric ring-linear polymer blends
Thomas C. O’Connor, Ting Ge, et al.
Related Content
Stress-controlled medium-amplitude oscillatory shear (MAOStress) of PVA–Borax
J. Rheol. (August 2024)
A strain stiffening theory for transient polymer networks under asymptotically nonlinear oscillatory shear
J. Rheol. (July 2017)
Exact solutions for oscillatory shear sweep behaviors of complex fluids from the Oldroyd 8-constant framework
Physics of Fluids (February 2018)
Non-Brownian Newtonian suspensions may be rate dependent in time sweep oscillatory shear flow
J. Rheol. (September 2020)
Unified interpretation of MAOS responses via experimentally decomposed material functions
J. Rheol. (October 2023)