Skip to Main content Skip to Navigation
Theses

Étude du comportement mécanique et de l'endommagement de composites thermoplastiques renforcés de fibres courtes de chanvre: approche expérimentale et modélisation

Abstract : Natural fibres are expected to have the ability to replace synthetics fibres as reinforcement for thermoplastics. A short plant fibres reinforced thermoplastics (polypropylene/hemp) is therefore studied in this PhD thesis. The processing temperature of PP allows the use of natural fibres. Moreover the hemp growing is easy in Lorraine. The testing specimens were made by compounding and injection moulding. Experimental characterization of the quasi-static thermomechanical behaviour of hemp composite was carried out with particular emphasis on the effect on strain rate, fibre loading and temperature. The damage is pointed out by load-unload-holding tests and in-situ infrared thermography recorder and revealed a « quasi-brittle » failure by matrix cracking regardless the hemp fibre loading. A complete statistical study in terms of spatial and orientation distribution of fibre was conducted by X-ray tomography and enables the development of an algorithm which generate a finite element model including the spatial reinforcement distribution and orientation distribution as well as geometrical features of fibres (L,Ø) Through this algorithm, the complicated interactions between isotropic elastic fibres are taken into account in the finite element modelling. Finally, finite element modelling of composite behaviour is intended. The elastic - progressive damage behaviour of the matrix is obtained in accordance to the micromechanism frame, in which PP is considered as a solid isotropic body weakened by penny-shaped cracks. This behaviour was implemented through a Fortran routine in abaqus software. This approach shows good prediction capabilities and gives opportunities to optimize this composite material
Document type :
Theses
Complete list of metadata

Cited literature [125 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-01750094
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 12:37:44 PM
Last modification on : Wednesday, March 31, 2021 - 5:30:03 PM
Long-term archiving on: : Friday, September 14, 2018 - 7:13:14 PM

File

DDOC_T_2013_0107_GEHRING.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01750094, version 1

Collections

Citation

Florian Gehring. Étude du comportement mécanique et de l'endommagement de composites thermoplastiques renforcés de fibres courtes de chanvre: approche expérimentale et modélisation. Autre. Université de Lorraine, 2013. Français. ⟨NNT : 2013LORR0107⟩. ⟨tel-01750094⟩

Share

Metrics

Record views

206

Files downloads

1259