In situ X-ray tomography investigation on damage mechanisms in short glass fibre reinforced thermoplastics: Effects of fibre orientation and relative humidity

Abstract

Damage mechanisms of reinforced polyamide 6,6 have been studied in 3D through in situ X-ray tomography tensile tests. 3D pictures of the microstructure have been taken during tensile tests to catch damage evolution in the bulk of material. The effects of relative humidity and orientation sampling are particularly investigated in this paper. Main mechanisms have been identified such as fibre failure, debonding, damage at fibre ends and matrix damage (cavitation, fibrillation, damage growth). Qualitative observations reveal that the mechanisms are very sensitive to orientation sampling and relative humidity of the specimen. A specific procedure was developed to propose a quantitative analysis of the results. This analysis shows that identified mechanisms not only have different proportions but also have different kinetics according to relative humidity and orientation sampling of the specimen.

Impact of fillers (short glass fibers and rubber) on the hydrolysis-induced embrittlement of polyamide 6.6

“…15), the discrepancy of strain at break values before degradation (12.5% vs 7.5%) can be attributed to the well-known polyamide plasticization effect. In terms of deformation mechanisms, wet conditions promote an increase in density and volume of matrix damage such as cavitation and fibrillation for a given fiber orientation [30]. However, it has also been proposed that water content modifies the interfacial properties between fibers and matrix, leading to fiber-matrix debonding [31,32].…”

Fatigue of short fibre reinforced polymers: from material process to fatigue life of industrial components

“…Considering the sensitivity of the material to humidity (see [2]), the material is first conditioned at MATEC Web of Conferences 165, 08003 (2018) https://doi.org/10.1051/matecconf/201816508003 FATIGUE 2018 50% relative humidity using an accelerated conditioning method described in the ISO 1110 standard.…”

Analysis of Impregnation Mechanism of Weft-Knitted Commingled Yarn Composites by Staged Consolidation and Laboratory X-Ray Computed Tomography

“…Higher energy X-ray beams, such as those in synchrotron facilities are more adapted to the in-situ µCT imaging which is required for the in-situ characterization at high time resolution and at resolutions lower than one micrometer. In-situ µCT analyses are more suitable to monitor damage (Böhm et al, 2015;Rolland et al, 2017;Yang et al, 2017;Jespersen et al, 2018;Wang et al, 2018), to characterize time dependent phenomena taking place during the process, such as the impregnation of reinforcement (Vilà et al, 2015;Sisodia et al, 2016;Larson and Zok, 2018) and the fiber bed compression (Latil et al, 2011;Ferré Sentis et al, 2017). In case the readers need more information about application of µCT characterization of polymer matrix composites, some reviews are already available in the literature (Maire and Withers, 2014;Duchene et al, 2018;Garcea et al, 2018).…”