Numerical modelling of entangled carbon fibre material under compression

Chatti, Fadhel; Poquillon, Dominique; Michon, Guilhem

doi:10.1016/j.commatsci.2018.04.045

Cited by 13 publications

(6 citation statements)

References 19 publications

(13 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This behaviour was attributed to friction between the fibres, as part of the fibre-fibre contacts are not cross-linked. This is consistent with experimental and numerical studies on the static compression of entangled fibres, where friction between the fibres plays an important role [14,15]. These studies indicate that the ECF material may constitute a good candidate to reduce vibrations in sandwich structures.…”

Section: Introductionsupporting

confidence: 87%

“…These avenues will also enrich the existing numerical and analytical models of materials involving entangled fibres. Currently, numerical models are developed for representative volume element (RVE) of entangled fibres [15] and future work includes the integration of cross-links in such models. Improving the repeatability of the fabrication process will also constitute an important step towards the integration of the ECF material in industrial structures.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

High damping and nonlinear vibration of sandwich beams with entangled cross-linked fibres as core material

Piollet

Fotsing

Ross

et al. 2019

Composites Part B: Engineering

Self Cite

View full text Add to dashboard Cite

This article investigates the use of a recently developed fibrous core material to increase vibration damping in sandwich beams. The entangled cross-linked fibre (ECF) material is made of short carbon fibres cross-linked with epoxy resin. Dry friction between fibres provides energy dissipation when the material is deformed. Previous measurements on the material are post-processed to provide a simplified viscoelastic description of the material, for an easier interpretation of subsequent structural testings. Two sandwich beams are compared with reference honeycomb beams: a sandwich beam with an ECF core, and a hybrid beam with a honeycomb core and an ECF insert. Steady-state tests are performed on both types of beams to obtain their frequency responses for different excitation levels, and the corresponding apparent loss factors are computed. The beam with a full ECF core shows an apparent loss factor more than ten times higher than the reference honeycomb beam. The hybrid sandwich beam provides an apparent loss factor four times higher than the reference honeycomb beam. All beams exhibit nonlinear softening responses consistent with a dry friction phenomenon in the material: the resonance frequencies decrease with increasing excitation amplitude, and damping increases then decreases again at very high amplitudes while remaining largely superior to that of the honeycomb beams. Transient impact testings are also presented for a qualitative comparison of the ECF and reference beams, and the ECF beams lead to shorter decay times compared to the reference beams.

show abstract

Section: Introductionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

High damping and nonlinear vibration of sandwich beams with entangled cross-linked fibres as core material

Piollet

Fotsing

Ross

et al. 2019

Composites Part B: Engineering

Self Cite

View full text Add to dashboard Cite

show abstract

“…The energy absorption to densification, U D , is defined as in Eq. 3, and all material properties are summarised in Table 3. In the literature of fibre network compression, the initial regime is composed of two sub-regions: an initial small-strain linear regime due to fibre rearrangement (Chatti et al 2018) or bending (Islam et al 2017), followed by a second regime controlled by fibre bending and buckling (Islam et al 2017. The response of the present networks showed no marked distinction between these two sub-regimes; this may be caused by a spatially distributed activation of the above 3 mechanisms, due to the random fibre orientation.…”

Section: Mechanical Responsementioning

confidence: 61%

“…The response of these foams undergoes two distinct regimes: an initial linear regime, followed gradually by strain stiffening. Unlike close-celled foams, fibre networks do not exhibit a marked transition to the densification regime (Picu 2011;Alimadadi et al 2018;Chatti et al 2018;. We thus define the densification stress and strain (r D and e D respectively) as the point where the instantaneous modulus takes the value dr=de ¼ 1:5E, with E denoting the stiffness of the initial linear regime; these points are depicted in Fig.…”

Section: Mechanical Responsementioning

confidence: 99%

Characterization and structural properties of bamboo fibre solid foams

2020

View full text Add to dashboard Cite

In this work, cellulose fibres extracted from bamboo culms were used to fabricate two types of cellular materials: rigid foams and fibrous networks. A relatively simple and low-technology fabrication method is presented, using natural binders and blowing agents to manufacture rigid foams, and fibrillation by partial hydrolysis in H2SO4 to manufacture fibrous networks. The compressive response is related to the internal microstructure and processing parameters. In the case of fibrous networks, the achievable relative density range is determined by the length of initial fibres and extent of external fibrillation. The compressive properties are dictated both by the density of the network and strength of the fibrous bridges, showing a linear stiffness-density relationship due to the length of fibres, and an inverse relationship at increased external fibrillation. The rigid foams showed an orthotropic internal microstructure but nearly isotropic compressive response, due to the influence of the interpenetrating void structure on the deformation and fracture mechanisms. The results show the potential of bamboo-fibre porous materials as low cost, lightweight structural materials.

show abstract

“…In order to check the repeatability of the results of the numerical simulation, three different geometries were generated. Indeed, in the previous works ( Chatti et al, 2018a( Chatti et al, , 2018b, we have checked the volume chosen for the simulation (a cubic millimetre), was a RVE in the morphological sense ( Kanit et al, 2003 ). It was then important to verify that we had a representative elementary volume for mechanics.…”

Section: Shear Testmentioning

confidence: 99%

Numerical analysis of shear stiffness of an entangled cross-linked fibrous material

Chatti

Michon

Poquillon

2020

International Journal of Solids and Structures

Self Cite

View full text Add to dashboard Cite

To cite this version:Fadhel Chatti, Christophe Bouvet, Guilhem Michon, Dominique Poquillon. Numerical analysis of shear stiffness of an entangled cross-linked fibrous material. a b s t r a c tThe objective of this paper is to understand and study the effect of morphological parameters on the shear stiffness of an entangled cross-linked fibrous material made with carbon fibres where some of the contacts are bonded by the epoxy resin. This current work presents a 3D finite element model using ABAQUS/Standard in order to characterize the mechanical behaviour of different carbon fibre networks rigidified by epoxy cross-links. Numerical simulations are achieved on a representative volume element (RVE) with the orientation distribution of the fibres based on a tested sample. Since not all the strands are perfectly separated, an equivalent diameter of fibre is determined to obtain the rigidity experimentally measured in shear. Then, an investigation of the influence of morphological descriptors, such as the distance between cross-links, distribution fibre orientations and junction properties, is carried out. For the entangled cross-linked fibrous material with a small fibre volume fraction, the relationship between the shear stiffness and the fibre volume fraction is a linear function whereas the relation between the shear stiffness and the distance between junctions is a power law with exponent of −3/2. The shear stiffness depends slightly on the twisting joint stiffness, and its relationship with the tension joint stiffness is a logarithmic function. The effect of fibre stiffness is also investigated by taking Young's modulus values corresponding to those of glass fibres, inox fibres or aramid fibres. A linear function is obtained between the shear stiffness and the Young's modulus. These results are consistent with the analytical models in the literature for a cross-linked fibrous material.

show abstract

Numerical modelling of entangled carbon fibre material under compression

Cited by 13 publications

References 19 publications

High damping and nonlinear vibration of sandwich beams with entangled cross-linked fibres as core material

High damping and nonlinear vibration of sandwich beams with entangled cross-linked fibres as core material

Characterization and structural properties of bamboo fibre solid foams

Numerical analysis of shear stiffness of an entangled cross-linked fibrous material

Contact Info

Product

Resources

About