Journal ArticleDOI
A Nonlinear Network Viscoelastic Model
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In this paper, a nonlinear constitutive equation for polymer melts and concentrated solutions is derived from a Lodge-Yamamoto type of network theory, where the network junctions are postulated to move nonaffinely in a well-defined manner.Abstract:
A nonlinear constitutive equation for polymer melts and concentrated solutions is derived from a Lodge‐Yamamoto type of network theory. The network junctions are postulated to move nonaffinely in a well‐defined manner. The functional form of the creation and destruction rates of junctions is assumed to depend on the average extension of the network strand and the absolute temperature in such a way to allow for the time‐temperature superposition principle. The theory shows good agreement with all data examined. The paper concludes with a strong flow problem (melt spinning). The results indicate the validity of the model in this flow regime.read more
Citations
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Instabilities in viscoelastic flows
TL;DR: In this article, the authors present a review of the latest developments as well as earlier work in this area, organized into the following categories: Taylor-Couette flows, instabilities in cone and plate-and-plate flows, parallel shear flows, extrudate distortions and fracture, Instabilities in shear flow with interfaces, extensional flows, and thermohydrodynamic instabilities.
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Viscoelasticity and dynamics of entangled polymers
TL;DR: In this paper, a review of the entanglement dynamics of flexible polymer chains from theoretical and experimental points of view is presented, and the validity and limitation of the models are discussed.
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Fracture and adhesion of soft materials: a review.
TL;DR: This review discusses the current state of the art on how soft materials break and detach from solid surfaces and defines the important length scales in the problem and in particular the elasto-adhesive length Γ/E, which controls the fracture mechanisms.
Journal ArticleDOI
Benchmark solutions for the flow of Oldroyd-B and PTT fluids in planar contractions
TL;DR: In this paper, the authors present very accurate numerical results for the vortex size, the vortex intensity and the Couette correction, in planar contraction flows of Oldroyd-B and PTT fluids, with both the linear and the exponential stress function, and with a solvent viscosity ratio equal to 1/9.
Journal ArticleDOI
Simulation of melt spinning including flow-induced crystallization: Part I. Model development and predictions
TL;DR: A mathematical model based on the formalism of Doufas et al. as discussed by the authors was developed for the simulation of both low and high-speed melt spinning including the combined effects of flow-induced crystallization (FIC), viscoelasticity, filament cooling, air drag, inertia, surface tension and gravity.
References
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Book
Viscoelastic properties of polymers
TL;DR: In this article, the authors describe the nature of Viscoelastic behavior of polymeric systems and approximate relations among the linear Viscoels and approximate interrelations among the Viscelastic Functions.