Approche intégrée pour estimer la durée de vie en fatigue de pièces thermoplastiques renforcés fibres courtes dans un cadre viscoélastique haute température

Abstract : The employment of short glass fibres reinforced thermoplastics is increasing in the automotive industry for hot environment applications. The design of components in such conditions and with this type of materials under fatigue loading must be optimized using a fatigue life assessment methodology. The heterogeneous fibres orientation distribution (FOD), due to the injection process should be considered.This work, funded by the Direction Générale de l’Armement et Région Poitou-Charentes, suggests an integrated approach from the injection process simulation to the assessment of the fatigue life at 110°C of injected components in a viscoelastic framework.The methodology here advanced is called “Through Process Modelling” (TPM). From the FOD in the component given by the injection simulation, the anisotropic effective local properties are estimated using viscoelastic homogenisation. The heterogeneous mechanical fields obtained by finite element simulations, for different types/levels of loading, are post-processed in order to get the input equivalent mechanical quantity of an energetic fatigue criterion giving the fatigue life of the component in each of these loading conditions.The identification of the fatigue criterion parameters and the validation of the whole methodology rely on an experimental fatigue database for a PA66GF30. Uniaxial tensile fatigue tests are carried out at 110°C in a climatic chamber, for 2 stress ratios (R = 0,1 and R = -1) and at 2Hz. They are performed for specimens cut out from injected plates with different orientations with respect to the flow direction.The methodology leads to very good predictions. The influence of the prediction of the FOD, input of the calculation chain, on the results is discussed.
Document type :
Theses
Liste complète des métadonnées

https://tel.archives-ouvertes.fr/tel-02080120
Contributor : Abes Star <>
Submitted on : Tuesday, March 26, 2019 - 2:53:31 PM
Last modification on : Wednesday, March 27, 2019 - 1:02:07 AM

File

2018ESMA0017_fouchier.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02080120, version 1

Collections

Citation

Nathan Fouchier. Approche intégrée pour estimer la durée de vie en fatigue de pièces thermoplastiques renforcés fibres courtes dans un cadre viscoélastique haute température. Autre. ISAE-ENSMA Ecole Nationale Supérieure de Mécanique et d'Aérotechique - Poitiers, 2018. Français. ⟨NNT : 2018ESMA0017⟩. ⟨tel-02080120⟩

Share

Metrics

Record views

89

Files downloads

20