Fiber motion and rheology of suspensions with uniform fiber orientation

Direct simulation for concentrated fibre suspensions in transient and steady state shear flows

“…Sepehr et al [5,6] compared these equations with experimental studies on concentrated fibre suspensions and they found some disagreement. On the other hand Barbosa and Bibbo [7] got good agreement for a fluid made with silicone oil and nylon fibres in dilute suspension. Another way to study suspension behaviour is to make a direct simulation where forces acting on each fibre included in a given volume are computed and used to calculate fibre motion and stress in the suspension.…”

“…After, the steady state flow is reached with a stable viscosity value. This viscosity evolution is in keeping with experimental results obtained in the literature [1,2,[5][6][7]41]; it has been obtained because fibres have different lengths. Using these equations, the normalized normal stress difference (N 1 /η 0γ ) has been simulated.…”

Rheological properties of short fiber filled polypropylene in transient shear flow

“…We call these smaller overshoots "reverse peaks" that we attribute to tumbling of some of the fibers. Barbosa and coworkers [34,35] have reported a similar behavior for Nylon fiber suspensions in PDMS. Even after reaching steady-state conditions in a positive creep experiment, some fibers are not totally aligned with the flow direction.…”

Flow induced fibre alignment in Mycoprotein paste

“…A considerable amount of work has been done on fibre alignment in polymer and composite systems (Barbosa & Bibbo, 2000). Composites with short fibres aligned in a preferred direction, possess advantages over those with random short fibres including higher strength, lighter weight, and a higher resistance to fracture, impact, fatigue, chemical attack or high temperatures (Guell & Papathanasiou, 1997).…”