Paper Number
SM45
Session
Polymers Solutions, Melts and Blends
Title
Medium-amplitude oscillatory shear (MAOS) predictions for the Johnson-Segalman non-affine deformation model
Presentation Date and Time
October 24, 2019 (Thursday) 9:05
Track / Room
Track 3 / Room 201
Authors
- Ramlawi, Nabil (University of Illinois at Urbana-Champaign, Mechanical Engineering)
- Ewoldt, Randy H. (University of Illinois at Urbana-Champaign, Department of Mechanical Science and Engineering)
Author and Affiliation Lines
Nabil Ramlawi and Randy H. Ewoldt
Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801
Speaker / Presenter
Ramlawi, Nabil
Text of Abstract
We report our derived medium-amplitude oscillatory shear (MAOS) signatures for the non-affine constitutive equation developed by Johnson and Segalman[1], which assumes that the microscale elements causing stress in the material slip compared to the continuum deformation. Following a recent approach developed by our group[2,3],a Bayesian credibility criterion is used to assess the credibility of this model compared to others, considering both discrete and continuous relaxation spectra, in describing frequency-dependent MAOS data for a polyisoprene polymer melt. The addition of the non-affine deformation model to the set of possible models improves the capability to infer material properties using MAOS. [1] M. W. Johnson and D. Segalman, “A model for viscoelastic fluid behavior which allows non-affine deformation,” J. Non-newtonian Fluid Mech., vol. 2, no. 3, pp. 255–270, May 1977. [2] J. B. Freund and R. H. Ewoldt, “Quantitative rheological model selection: Good fits versus credible models using Bayesian inference,” J. Rheology, vol. 59, no. 3, pp. 667–701, 2015. [3] L. Martinetti, J. M. Soulages, and R. H. Ewoldt, “Continuous relaxation spectra for constitutive models in medium-amplitude oscillatory shear,” J. Rheology., vol. 62, no. 5, pp. 1271–1298, 2018.