Taxonomy of fibre mat misalignments in pultruded GFRP bridge decks

Characterisation of local damage in pultruded GFRP road bridge decks with random fibre mat misalignments

“…At this point, it is useful to briefly summarise the taxonomy of fibre mat misalignments defined in a previous study [7], which is of direct relevance to the study presented in this paper. In that earlier study, six different categories of misalignment were identified within the junctions of different batches of the very pultruded GFRP deck system used in the present study.…”

“…The strategy for quantifying the fibre mat misalignments within each junction is described in [7]. Each junction was evaluated with respect to three independent misalignment categories:…”

“…Under the patch loads, these junctions transmit high, multi-directional stress resultants whether the deck runs transversely as in the UK's West Mill bridge [5] or longitudinally as in the UK's Frampton Cotterell bridge [6]. Such large stress resultants transmitted through the small volumes of the junctions lead to high local stresses that are further magnified by the randomly misaligned fibre mat layers present in the junction due to imperfect quality control during the manufacturing process [7]. Misalignments refer to out-of-plane deviations of the fibre mats (for example, waviness, wrinkles and folds) from their optimal trajectories; that is, the trajectories that produce the greatest load-carrying capacity in service.…”

“…This study also presented a manual method for mapping the misalignments. A subsequent study [7] built on this initial investigation by presenting a digitized method of mapping the misalignments. This study also presented a dual scheme for defining a taxonomy of these misalignments, including the geometry and the origins in specific features of the manufacturing process.…”

Mesoscale Process Modeling of a Thick Pultruded Composite with Variability in Fiber Volume Fraction

“…In addition to this global V f variability, a micro/meso-scale variability in V f is inevitable due to intra-roving resin-rich layers and randomly distributed filament within the inter-roving regions. Detailed analyses of fiber misalignment, fiber mat misalignment, resin-rich areas, and void topology in pultrusion products have been performed via optical micrography, Fourier transformation, and computational tomography [34][35][36]. In addition to the characterization of the variability in fiber distribution, its effects on a pultruded bridge deck profile's ultimate properties/performance were investigated in [37].…”