The Experts below are selected from a list of 1143 Experts worldwide ranked by ideXlab platform
Francesco Aymerich - One of the best experts on this subject based on the ideXlab platform.
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Effect of Z-pinning on the impact resistance of composite Laminates with different Layups Part A Applied science and manufacturing
Composites, 2018Co-Authors: L. Francesconi, Francesco AymerichAbstract:The paper presents the results of an experimental investigation into the effect of Z-pinning on the impact resistance of composite Laminates with different multi-directional Layups. Unpinned and pinned [02/902]s, [02/±45]s and [0/±45/90]s carbon/epoxy samples were subjected to low-velocity impacts resulting in damage severities ranging from barely visible damage to full Laminate penetration. The responses to impact of the Laminates were characterized in terms of damage evolution, load-carrying capacity, and resistance to perforation and penetration. It was found that even though Z-pins are not capable of delaying the onset of delamination, they significantly reduce delamination size for high-energy impacts. Z-pinning improves the resistance to perforation and penetration of [02/902]s, Laminates, while it does not significantly affect that of [02/±45]s and [0/±45/90]s samples. The dependence of the efficacy of Z–pins on the Laminate Layup is attributed to the different distribution of the delaminations through the thickness of the investigated Laminates.
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Effect of Z-pinning on the impact resistance of composite Laminates with different Layups
Composites Part A: Applied Science and Manufacturing, 2018Co-Authors: L. Francesconi, Francesco AymerichAbstract:Abstract The paper presents the results of an experimental investigation into the effect of Z-pinning on the impact resistance of composite Laminates with different multi-directional Layups. Unpinned and pinned [02/902]s, [02/±45]s and [0/±45/90]s carbon/epoxy samples were subjected to low-velocity impacts resulting in damage severities ranging from barely visible damage to full Laminate penetration. The responses to impact of the Laminates were characterized in terms of damage evolution, load-carrying capacity, and resistance to perforation and penetration. It was found that even though Z-pins are not capable of delaying the onset of delamination, they significantly reduce delamination size for high-energy impacts. Z-pinning improves the resistance to perforation and penetration of [02/902]s, Laminates, while it does not significantly affect that of [02/±45]s and [0/±45/90]s samples. The dependence of the efficacy of Z–pins on the Laminate Layup is attributed to the different distribution of the delaminations through the thickness of the investigated Laminates.
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Impact damage resistance of thin stitched carbon/epoxy Laminates
Journal of Physics: Conference Series, 2015Co-Authors: L. Francesconi, Francesco AymerichAbstract:The study examines the influence of through-thickness stitching on the damage response of thin cross-ply carbon/epoxy Laminates subjected to low-velocity impacts. Instrumented impact tests were carried out on unstitched and polyethylene stitched Laminates and the resulting damage was assessed in detail by X-radiography analyses. The results of the observations carried out during the experimental analyses are illustrated and discussed to identify the mechanical role played by through-thickness reinforcement and to highlight the influence of the Laminate Layup on the impact resistance of stitched Laminates.
Adrian Murphy - One of the best experts on this subject based on the ideXlab platform.
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Experimental evaluation of residual tensile strength of hybrid composite aerospace materials after low velocity impact
Composites Part B: Engineering, 2019Co-Authors: Damghani, Nuri Ersoy, Michal Piorkowski, Adrian MurphyAbstract:Abstract Although much work has considered hybridised Carbon and Glass Fibre Reinforced Polymers to positively influence the performance of composite structures when subjected to transverse impact loading, there is limited understanding considering low energy impact levels (≤10J) - in particular how variation in impact energy influences damage formation and post impact tensile strength. Herein, low velocity impact and residual tensile strength after impact tests are completed on four Laminate designs (one pure Carbon Laminate Layup and three hybrid Carbon and Glass Layups). Three repeat tests and three graduated low energy level impacts (≤10 J) are considered along with pristine Laminate performance. The impact response was evaluated in terms of surface damage size by visual inspection, and the evolution of peak force and stiffness with impact energy level. The contribution of this paper is the first presentation of a detailed experimental study on the tensile performance of hybrid composite materials subjected to a graduated range of low energy level impacts. The methodical experimental work demonstrates how the hybrid Layup influences the scale and form of damage. By distributing the glass plies through the Laminate, as opposed to clustering the glass plies at the inner or outer mould surfaces, more favourable residual tensile strength and strain to failure is demonstrated.
Juan M. Fernandez - One of the best experts on this subject based on the ideXlab platform.
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Inducing bistability in Collapsible Tubular Mast booms with thin-ply composite shells
Composite Structures, 2019Co-Authors: Andrew J. Lee, Juan M. FernandezAbstract:Abstract Bistable rollable booms are favorable when a low strain energy requirement for the coiled state is imposed and have more controllable deployment when compared to monostable booms. An inextensional analytical model describing the bending deformation mechanics of Collapsible Tubular Mast (CTM) booms was used to determine how design variables induce bistability, or the existence of two strain energy wells in the rolled-up and unrolled states. The effects of varying lamina material, Laminate Layup, and shell arc geometries between different inner and outer shell segments on the second strain energy well and stiffness properties were determined for boom cross-sections formed by circular segments. The full design space for two-walled composite CTM booms was explored to evaluate the validity of the developed analytical model. Optimized CTM boom designs were experimentally characterized for comparisons against model results. The model under-predicted the stable coiled diameter of the co-cured two-walled booms by up to 8.9% and 23.4% for the individual thin shells wrapped alone.
L. Francesconi - One of the best experts on this subject based on the ideXlab platform.
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Effect of Z-pinning on the impact resistance of composite Laminates with different Layups Part A Applied science and manufacturing
Composites, 2018Co-Authors: L. Francesconi, Francesco AymerichAbstract:The paper presents the results of an experimental investigation into the effect of Z-pinning on the impact resistance of composite Laminates with different multi-directional Layups. Unpinned and pinned [02/902]s, [02/±45]s and [0/±45/90]s carbon/epoxy samples were subjected to low-velocity impacts resulting in damage severities ranging from barely visible damage to full Laminate penetration. The responses to impact of the Laminates were characterized in terms of damage evolution, load-carrying capacity, and resistance to perforation and penetration. It was found that even though Z-pins are not capable of delaying the onset of delamination, they significantly reduce delamination size for high-energy impacts. Z-pinning improves the resistance to perforation and penetration of [02/902]s, Laminates, while it does not significantly affect that of [02/±45]s and [0/±45/90]s samples. The dependence of the efficacy of Z–pins on the Laminate Layup is attributed to the different distribution of the delaminations through the thickness of the investigated Laminates.
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Effect of Z-pinning on the impact resistance of composite Laminates with different Layups
Composites Part A: Applied Science and Manufacturing, 2018Co-Authors: L. Francesconi, Francesco AymerichAbstract:Abstract The paper presents the results of an experimental investigation into the effect of Z-pinning on the impact resistance of composite Laminates with different multi-directional Layups. Unpinned and pinned [02/902]s, [02/±45]s and [0/±45/90]s carbon/epoxy samples were subjected to low-velocity impacts resulting in damage severities ranging from barely visible damage to full Laminate penetration. The responses to impact of the Laminates were characterized in terms of damage evolution, load-carrying capacity, and resistance to perforation and penetration. It was found that even though Z-pins are not capable of delaying the onset of delamination, they significantly reduce delamination size for high-energy impacts. Z-pinning improves the resistance to perforation and penetration of [02/902]s, Laminates, while it does not significantly affect that of [02/±45]s and [0/±45/90]s samples. The dependence of the efficacy of Z–pins on the Laminate Layup is attributed to the different distribution of the delaminations through the thickness of the investigated Laminates.
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Impact damage resistance of thin stitched carbon/epoxy Laminates
Journal of Physics: Conference Series, 2015Co-Authors: L. Francesconi, Francesco AymerichAbstract:The study examines the influence of through-thickness stitching on the damage response of thin cross-ply carbon/epoxy Laminates subjected to low-velocity impacts. Instrumented impact tests were carried out on unstitched and polyethylene stitched Laminates and the resulting damage was assessed in detail by X-radiography analyses. The results of the observations carried out during the experimental analyses are illustrated and discussed to identify the mechanical role played by through-thickness reinforcement and to highlight the influence of the Laminate Layup on the impact resistance of stitched Laminates.
Xiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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impact damage and cai strength of a woven cfrp material with fire retardant properties
Composites Part B-engineering, 2016Co-Authors: Ioannis K Giannopoulos, E E Theotokoglou, Xiang ZhangAbstract:Abstract This paper presents the interrogation of low velocity impact and compression after impact test results on a woven fibre composite having a fire retardant, syntactic core, two phase epoxy matrix. The results of the study were to be utilized in a decision making process regarding the appropriateness of the material usage in question for a certain aerospace application. The epoxy matrix of the material system had dispersed black-pigmented particles with flame-retarding properties. Impact tests were performed at five impact energy levels. Two different Laminate Layup configurations were tested. Visual and C-Scan inspection were conducted, in order to observe the extent of the damage in the composite material. Compression tests were performed to study the residual strength after impact. Analytical formulation correlations with the test results presented opportunities for quantifying the interfacial fracture toughness resistance. Micro-graphs of the specimen's cross section were also produced in an effort to observe the fractured sections and characterise the various fracture mechanisms involved. The results exploitation in terms of design decision making are presented.
