Experimental analysis of the porosity of randomly packed rigid fibers

Rheology of concentrated suspensions of non-colloidal rigid fibres

“…Both shear and normal viscosities present a similar algebraic divergence in ≈(φ m − φ) −1 in stark contrast to that in (φ m − φ) −2 observed for suspensions of spheres near the jamming point. The maximum volume fraction φ m is seen to decrease with increasing aspect ratio, similar to the dry packing of rigid fibres found in experiments (Rahli et al 1999), see figure 5(a). However, no inference about the general structure of the suspension at jamming is possible for A < 15, because comparisons with estimates of maximum random packing (Williams & Philipse 2003) do not clearly indicate that the orientation distribution has organised.…”

Experimental study of the porosity of loose stacks of stiff cylindrical fibres: Influence of the aspect ratio of fibres

“…In Figure 7 the laws of variations are shown for the two types of stacks. We have also mentioned the results of the porosity measurements of 3D stacks found by Milewski [3], Nardin [4], Rahli [5,6] and Parkhouse [8] and we have specified the nature and the characteristics of the fibres used.…”

“…Rahli [5,6] proposed a porosity variation law based on the excluded volume model elaborated by Onsager [7]. This volume is defined as the mean portion of the space which one fibre excludes to the centre of the surrounding fibres.…”

“…Rahli [5,6] studied loose and close packing of Nylon or metal (copper, bronze) fibres. He, moreover, proposed a model based on the excluded volume determined by Onsager [7].…”

On contact numbers in random rod packings

“…The random rod packing is a valuable reference for packed granular matter composed of elongated particles as can be found in fiber-reinforced and other fibrous materials [1][2][3][4], and anisotropic powders [5,6]. This reference packing is a stacking of randomly oriented, rigid rods with a maximum particle volume-fraction uniquely determined by the rod aspect ratio [5].…”