Influence of orthogonal prestrain on the viscoelastic behaviour of highly-filled elastomers

Aurélie Azoug (1) , Anders Thorin (1) , Robert Nevière (2) , Rachel-Marie Pradeilles-Duval (1) , Andrei Constantinescu (1)

1 LMS - Laboratoire de mécanique des solides
2 DGA Maitrise NRBC - Centre d'Études du Bouchet

Highly filled elastomers exhibit a complex nonlinear mechanical behaviour that is difficult to characterize experimentally. This paper presents a Dynamic Mechanical Analysis (DMA) method coupled with orthogonal prestrains, applied in two distinct steps. A localization operator between measurements at the arms of a cross shaped specimen and the stress and strain fields at its center was determined using elastic small strain finite element computations. The operator makes estimating the storage and loss moduli at the center of the specimen possible. A mathematical model is then fitted to the moduli values. These results are compared to DMA measurements of highly filled elastomers under uniaxial prestrain. Although the storage and loss moduli increase with the prestrain under both loadings, the nonlinear behaviour is quantitatively modified by adding an orthogonal prestrain. In addition, the modification of the behaviour under a horizontal prestrain is cancelled out by an increase of the vertical prestrain, which may be explained by fillers aligning in the direction of the prestrain.

Mots clés: Prestrain; Solid propellant; Fillers alignment; Highly-filled elastomer; Dynamic Mechanical Analysis

Domaines: Mécanique des solides [physics.class-ph]; Mécanique des structures [physics.class-ph]; Vibrations [physics.class-ph]; Génie mécanique [physics.class-ph]; Dynamique, vibrations; Structures

Aurélie Azoug, Anders Thorin, Robert Nevière, Rachel-Marie Pradeilles-Duval, Andrei Constantinescu. Influence of orthogonal prestrain on the viscoelastic behaviour of highly-filled elastomers. Polymer Testing, 2013, 32 (2), pp.375-384. ⟨10.1016/j.polymertesting.2012.12.005⟩. ⟨hal-01402496⟩