Rheology of fiber suspensions in viscoelastic media: Experiments and model predictions

The rheological behavior of suspensions of short glass fibers in different fluids has been studied. Transient tests on presheared samples of fiber suspensions in Boger fluids showed that orientation of fibers not only depends on the strain, but also on the rate-of-strain. The experimental results show that upon increasing fiber concentration and/or fiber aspect ratio, the steady shear material functions of fiber suspensions increase at low shear rates, whereas at high shear rates, these material functions approach those of the matrix and become almost independent of fiber characteristics. A rheological model based on the modified Jeffery equation for the fiber motion and a Hookean energy model, formulated within the GENERIC framework, for the matrix has been developed to quantitatively predict experimental data for suspensions of fibers in different fluids. A quantitative comparison of experimental data with model predictions shows the ability of the model to predict the rheological behavior of fiber susp...

[1]  Miroslav Grmela,et al.  Bracket formulation of dissipative time evolution equations , 1985 .

[2]  M. Grmela,et al.  Modelling the rheological behaviour of fibre suspensions in viscoelastic media , 1994 .

[3]  P. Carreau,et al.  Rheology of short glass fiber reinforced polypropylene , 1992 .

[4]  T. Kitano,et al.  Relative viscosities of polymer melts filled with inorganic fillers , 1980 .

[5]  M. Narkis,et al.  Fibre orientation and rheology in short fibre reinforced thermoplastics , 1988 .

[6]  M. Grmela.  Dependence of the Stress Tensor on the Intramolecular Viscosity , 1989 .

[7]  James L White,et al.  The influence of particle size and surface coating of calcium carbonate on the rheological properties of its suspensions in molten polystyrene , 1983 .

[8]  G. Batchelor,et al.  The stress generated in a non-dilute suspension of elongated particles by pure straining motion , 1971, Journal of Fluid Mechanics.

[9]  R. Bird,et al.  An encapsulted dumbbell model for concentrated polymer solutions and melts I. Theoretical development and constitutive equation , 1983 .

[10]  A. Mutel,et al.  Rheological Properties of Suspensions in Newtonian and Non-Newtonian Fluids , 1985 .

[11]  Miroslav Grmela,et al.  Conformation tensor rheological models , 1987 .

[12]  H. Laun.  Orientation effects and rheology of short glass fiber-reinforced thermoplastics , 1984 .

[13]  Suresh G. Advani,et al.  Fiber–fiber interactions in homogeneous flows of nondilute suspensions , 1991 .

[14]  B. Edwards,et al.  Poisson bracket formulation of viscoelastic flow equations of differential type: A unified approach , 1990 .

[15]  Miroslav Grmela,et al.  Dynamics and thermodynamics of complex fluids. I. Development of a general formalism , 1997 .

[16]  James L White,et al.  Shear flow rheological properties, fiber damage, and mastication characteristics of aramid-, glass-, and cellulose-fiber-reinforced polystyrene melts , 1980 .

[17]  M. Grmela.  Hamiltonian dynamics of incompressible elastic fluids , 1988 .

[18]  Suresh G. Advani,et al.  The Use of Tensors to Describe and Predict Fiber Orientation in Short Fiber Composites , 1987 .

[19]  C. Cohen,et al.  ORIENTATION IN SIMPLE SHEAR FLOW OF SEMI-DILUTE FIBER SUSPENSIONS 2. HIGHLY ELASTIC FLUIDS , 1996 .

[20]  P. Carreau,et al.  Highly elastic‐constant vicosity fluids , 1983 .

[21]  A. Ramazani,et al.  Rheological modelling of short fiber thermoplastic composites , 1997 .

[22]  Charles L. Tucker,et al.  Orthotropic closure approximations for flow-induced fiber orientation , 1995 .

[23]  J. Azaiez,et al.  Investigation of the abrupt contraction flow of fiber suspensions in polymeric fluids , 1997 .

[24]  Robert L. Powell,et al.  Rheological Properties of Rodlike Particles in a Newtonian and a Non‐Newtonian Fluid , 1986 .

[25]  P. Lafleur,et al.  Suspensions of fibers in viscoelastic fluids: Rheology , 1998 .

[26]  Y. Im,et al.  Modified hybrid closure approximation for prediction of flow-induced fiber orientation , 1999 .

[27]  M. Grmela.  Hamiltonian mechanics of complex fluids , 1989 .

[28]  R. Schröder.  Der Einfluß der elastischen Eigenschaften des Trägermediums auf das Fließverhalten von Kugel- und Fasersuspensionen , 1986 .

[29]  S. Güçeri,et al.  On the Description of the Orientation State for Fiber Suspensions in Homogeneous Flows , 1989 .

[30]  Miroslav Grmela,et al.  Bracket formulation of dissipative fluid mechanics equations , 1984 .

[31]  C. L. Tucker,et al.  Orientation Behavior of Fibers in Concentrated Suspensions , 1984 .

[32]  T. Kitano,et al.  Shear flow rheological properties of vinylon- and glass-fiber reinforced polyethylene melts , 1984 .

[33]  H. Kato,et al.  The flow behavior of fiber suspensions in Newtonian fluids and polymer solutions. , 1986 .

[34]  S. Advani,et al.  Characterization of orientation clustering in short‐fiber composites , 1990 .

[35]  R. Schrder.  Der Einflu der elastischen Eigenschaften des Trgermediums auf das Flieverhalten von Kugel- und Fasersuspensionen: I. Flieverhalten in Scherstrmungen , 1986 .

[36]  A. Ramazani,et al.  VOLUME PRESERVING RHEOLOGICAL MODELS FOR POLYMER MELTS AND SOLUTIONS USING THE GENERIC FORMALISM , 1999 .

[37]  M. Kamal,et al.  The prediction of flow and orientation behavior of short fiber reinforced melts in simple flow systems , 1989 .

[38]  G. B. Jeffery.  The motion of ellipsoidal particles immersed in a viscous fluid , 1922 .

[39]  Robert L. Powell,et al.  Rheology of suspensions of rodlike particles , 1991 .

[40]  T. Kitano,et al.  Fibre degradation during processing of short fibre reinforced thermoplastics , 1989 .

[41]  Suresh G. Advani,et al.  Closure approximations for three‐dimensional structure tensors , 1990 .

[42]  Robert C. Armstrong,et al.  A Rheological Equation of State for Semiconcentrated Fiber Suspensions , 1984 .

[43]  James L. White,et al.  The influence of titanium dioxide on the rheological and extrusion properties of polymer melts , 1976 .

[44]  A. B. Metzner,et al.  The rheology, fiber orientation, and processing behavior of fiber‐filled fluids , 1992 .

[45]  Miroslav Grmela,et al.  Dynamics and thermodynamics of complex fluids. II. Illustrations of a general formalism , 1997 .