%0 Journal Article %T Cyclic behaviour of short glass fiber reinforced polyamide: experimental study and constitutive equations %+ MMA %+ Laboratoire de mécanique des solides (LMS) %+ MMA %+ PSA Peugeot - Citroën (PSA) %A Launay, Antoine %A Maitournam, Habibou %A Marco, Yann %A Szmytka, Fabien %Z WOS %< avec comité de lecture %@ 0749-6419 %J International Journal of Plasticity %I Elsevier %V 27 %N 8 %P 1267-1293 %8 2011 %D 2011 %R 10.1016/j.ijplas.2011.02.005 %K Cyclic loading %K Constitutive behaviour %K Elasto-viscoplastic material %K Polymeric material %K Mechanical testing %Z Engineering Sciences [physics]/Mechanics [physics.med-ph]/Materials and structures in mechanics [physics.class-ph] %Z Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph] %Z Engineering Sciences [physics]/Materials %Z Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph] %Z Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph]Journal articles %X Polymer matrix composites are widely used in the automotive industry and undergo fatigue loadings. The investigation of the nonlinear cyclic behaviour of such materials is a required preliminary work for a confident fatigue design, but has not involved many publications in the literature. This paper presents an extensive experimental study conducted on a polyamide 66 reinforced with 35 wt% of short glass fibres (PA66 GF35), at room temperature. The material was tested in two conditions: dry-as-moulded (DAM) and at the equilibrium with air containing 50% of relative humidity (RH50). An exhaustive experimental campaign in tensile mode has been carried out, including various strain or stress rates, complex mechanical histories and local thermo-mechanical recordings. Such an extended database allowed us to highlight several complex physical phenomena: viscoelastic effects at different time scales, irrecoverable mechanisms, non-linear kinematic hardening, non-linear viscous flow rule, cyclic softening. Taking into account this advanced analysis, a constitutive model describing the cyclic behaviour is proposed. As the experimental database only includes uniaxial tensile tests, the general 3D anisotropic frame is reduced to an uniaxial model valid for a specific orientation distribution. The robust identification process is based on tests which enable the uncoupling between the underlined mechanical features. This strategy leads to a model which accurately predicts the cyclic behaviour of conditioned as well as dry materials under complex tensile loadings. %G English %L hal-00651216 %U https://hal.science/hal-00651216 %~ UNIV-BREST %~ X %~ INSTITUT-TELECOM %~ ENSMP %~ ENSTA-BRETAGNE %~ CNRS %~ X-LMS %~ X-DEP %~ X-DEP-MECA %~ ENSMP_LMS %~ PARISTECH %~ ENSTA-BRETAGNE-LBMS %~ ENIB %~ PSL %~ ENSMP_DEP_MM %~ ENSMP-PSL %~ TEST3-HALCNRS