Analysis of frictional behaviour of carbon dry woven reinforcement

Abstract

During the preforming stage of woven reinforcement, in the first step of the RTM process, frictional phenomenon occurring at the tool/reinforcement interfaces and the reinforcement/reinforcement interfaces is one of the key parameters of the forming process. This behaviour must be correctly taken into account when modelling the process and a better understanding of the contact and friction phenomena occurring during the woven fabric preforming process is necessary for realistic simulation of the preforming process.Although some existing studies concerning friction of reinforcement have been published, the complex frictional behaviour of fabrics is still not completely clear.The experimental characterization of the frictional behaviour of a specific carbon woven reinforcement (G1151) used for aeronautical applications, is the aim of this paper, and three interfaces have been studied (G1151/G1151, G1151/Plexiglas, G1151/Aluminium). The Coulomb coefficients of friction occurring during contact between two layers of fabric and between the fabric and other materials have been determined. The effect of the variation of the normal pressure and the temperature on the frictional behaviour of this reinforcement has also been analysed. Comparisons between several frictional models, described in the literature, are also conducted, associated with these experimental results.This study highlights a significant tribological anisotropy of the G1151 reinforcement and a dependence of the frictional characteristics on the applied pressure and the temperatureInternational audienceDuring the preforming stage of woven reinforcement, in the first step of the RTM process, frictional phenomenon occurring at the tool/reinforcement interfaces and the reinforcement/reinforcement interfaces is one of the key parameters of the forming process. This behaviour must be correctly taken into account when modelling the process and a better understanding of the contact and friction phenomena occurring during the woven fabric preforming process is necessary for realistic simulation of the preforming process.Although some existing studies concerning friction of reinforcement have been published, the complex frictional behaviour of fabrics is still not completely clear.The experimental characterization of the frictional behaviour of a specific carbon woven reinforcement (G1151) used for aeronautical applications, is the aim of this paper, and three interfaces have been studied (G1151/G1151, G1151/Plexiglas, G1151/Aluminium). The Coulomb coefficients of friction occurring during contact between two layers of fabric and between the fabric and other materials have been determined. The effect of the variation of the normal pressure and the temperature on the frictional behaviour of this reinforcement has also been analysed. Comparisons between several frictional models, described in the literature, are also conducted, associated with these experimental results.This study highlights a significant tribological anisotropy of the G1151 reinforcement and a depe...

An Analytical Model for the Tension-Shear Coupling of Woven Fabrics with Different Weave Patterns under Large Shear Deformation

“…Obviously, when ϕ ≤ ϕ L , the dissipation energy is zero. When ϕ > ϕ L , dW com can be achieved by substituting Equations (25) and (26) into Equations (22) and (23) and then into Equation (20). Finally, the expression of dW com is achieved:…”

Reibverhalten von trockenen Faserstrukturen aus einem direkten Faserablageprozess

“…In den meisten Fällen sind dabei flächi-ge Textilien wie Gewebe oder Gelege Gegenstand der Versuche, häufig in Verbindung mit einem Matrixsystem als Prepreg (thermoplastisch oder duromer) [13,14,[24][25][26][27][28][29][30][31]. Die untersuchten Reibpaarungen sind in erster Linie Faser bzw.…”

“…Dieses bei thermoplastischen Schmelzen übliche Verhalten lässt sich allerdings nicht nur bei der Paarung P/P und P/M [25,29] beobachten, sondern wurde auch für F/F und F/M nachgewiesen [13,28,30]. Die wohl wichtigste Einflussgröße auf den Koeffizienten der Reibung ist allerdings die Faserorientierung in Relation zu der Abzugsrichtung.…”

“…Bei unidirektionalen Textilien und der Paarung F/F ist der Koeffizient der Reibung bei faserparallelem Abzug (0°/0°) in etwa doppelt so groß, wie bei einer orthogonalen Anordnung (0°/90°) [14,26,31]. Wenn auch nicht so ausgeprägt, zeigt sich dieser Effekt ebenfalls bei den Paarungen F/M und P/M [13,25].…”

Development of an experimental bench to reproduce the tow buckling defect appearing during the complex shape forming of structural flax based woven composite reinforcements

“…For the in-plane shear behaviour and the identification of the locking shear angle, bias-tests or picture-frame tests can be conducted [27]. The determination of the tensile [28,29], bending [2,30], friction [31][32][33] behaviours or the identification of the permeability [21,34] are commonly used to identify limits of behaviour, independently of the preforming process. Due to the difficulty to identify all the causes leading to the appearance of the tow buckling defect, this paper proposes to study it independently of the process by using a specially designed experimental bench.…”