Date of Award

10-19-2023

Publication Type

Thesis

Degree Name

M.A.Sc.

Department

Mechanical, Automotive, and Materials Engineering

Keywords

Glass fibre;Long Fibre Thermoplastic;Mechanical characterization;Moisture content;Polyamide6;Strain rate sensitivity

Supervisor

William Altenhof

Rights

info:eu-repo/semantics/openAccess

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Abstract

In this study the tensile properties at different loading rates as well as shear properties of a direct-compounded compression-moulded Polyamide6 (PA6)/glass long fibre thermoplastic (LFT-D) material with a fibre weight content of 30% were investigated. The effects of moisture on the anisotropic mechanical and material properties of Glass/PA6 LFT materials were examined by testing at four different material directions of 0°, +45°, ˗45°, and 90°. In order to study the effect of tensile loading rate on this material, different nominal strain rates ranging from 0.0001 1/s to 150 1/s were examined. Under quasi-static loading, at a 2% moisture content, the material’s behaviour shifted from brittle to ductile under tension and shear loads. The presence of moisture reduced tensile strength and elastic modulus by up to 33% and 50%, respectively. However, increasing failure elongation by up to 323%, resulting in up to a 328% increase in tensile toughness. Furthermore, moisture significantly decreased the shear modulus by 16% to 30% and the ultimate shear strength by 13% to 29% in different material directions. Conversely, under dynamic loading, moisture content did not have a significant effect on PA6/Glass LFT materials, and both dried and undried conditions exhibited brittle behaviour. In the 0° material direction, the undried samples showed an increase of 93% in Young's modulus and 172% in ultimate tensile strength as a result of increasing strain rate, whereas the dried samples showed increases of 76% and 97%. Tensile strength reached 293.8 MPa and 276.7 MPa for undried and dried samples, respectively, in this particular material direction. Notably, the material exhibited significant strain rate sensitivity, especially in undried material conditioning.

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