The Experts below are selected from a list of 3126 Experts worldwide ranked by ideXlab platform
Maria Carolina Seghini - One of the best experts on this subject based on the ideXlab platform.
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Environmentally Friendly Surface Modification Treatment of Flax Fibers by Supercritical Carbon Dioxide
Molecules, 2020Co-Authors: Maria Carolina Seghini, Fabienne Touchard, Jacopo Tirillo, Laurence Chocinski-arnault, Vincent Placet, Camille François, Laurent Plasseraud, Maria Paola Bracciale, Fabrizio SarasiniAbstract:The present work investigates the effects of an environmentally friendly treatment based on supercritical carbon dioxide (scCO2) on the interfacial adhesion of flax fibers with thermoset matrices. In particular, the influence of this green treatment on the mechanical (by Single Yarn tensile test), thermal (by TGA), and chemical (by FT-IR) properties of commercially available flax Yarns was preliminary addressed. Results showed that scCO2 can significantly modify the biochemical composition of flax fibers, by selectively removing lignin and hemicellulose, without altering their thermal stability and, most importantly, their mechanical properties. Single Yarn fragmentation test results highlighted an increased interfacial adhesion after scCO2 treatment, especially for the vinylester matrix, in terms of reduced debonding and critical fragment length values compared to the untreated Yarns by 18.9% and 15.1%, respectively. The treatment was less effective for epoxy matrix, for which debonding and critical fragment length values were reduced to a lesser extent, by 3.4% and 3.7%, respectively.
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interfacial adhesion assessment in flax epoxy and in flax vinylester composites by Single Yarn fragmentation test correlation with micro ct analysis
Composites Part A-applied Science and Manufacturing, 2018Co-Authors: Maria Carolina Seghini, Fabienne Touchard, Fabrizio Sarasini, Laurence Chocinskiarnault, David Mellier, Jacopo TirilloAbstract:Abstract Despite the academic interest in using plant fibres as reinforcement in polymer composites to replace glass fibres, the industrial exploitation of resulting composites in semi- or structural applications is still limited. This is mainly due to the poor adhesion at the plant fibre/polymer matrix interface dictated by their surface chemistry and strong hydrophilic behaviour. In the present work, an assessment of the interfacial adhesion at the Yarn scale has been carried out. Fragmentation tests have been performed on flax/epoxy and flax/vinylester Single Yarn composites. High-resolution microtomography has allowed a 3-D reconstruction of the breaking area of the flax Yarn. The flax/epoxy system has shown the lowest values of critical fragment length and interfacial debonding length, and the highest values of IFSS. For both epoxy and vinylester samples, it was found that the breakage of flax has been mainly concentrated in the peripheral zone of the Yarn.
Fabienne Touchard - One of the best experts on this subject based on the ideXlab platform.
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Environmentally Friendly Surface Modification Treatment of Flax Fibers by Supercritical Carbon Dioxide
Molecules, 2020Co-Authors: Maria Carolina Seghini, Fabienne Touchard, Jacopo Tirillo, Laurence Chocinski-arnault, Vincent Placet, Camille François, Laurent Plasseraud, Maria Paola Bracciale, Fabrizio SarasiniAbstract:The present work investigates the effects of an environmentally friendly treatment based on supercritical carbon dioxide (scCO2) on the interfacial adhesion of flax fibers with thermoset matrices. In particular, the influence of this green treatment on the mechanical (by Single Yarn tensile test), thermal (by TGA), and chemical (by FT-IR) properties of commercially available flax Yarns was preliminary addressed. Results showed that scCO2 can significantly modify the biochemical composition of flax fibers, by selectively removing lignin and hemicellulose, without altering their thermal stability and, most importantly, their mechanical properties. Single Yarn fragmentation test results highlighted an increased interfacial adhesion after scCO2 treatment, especially for the vinylester matrix, in terms of reduced debonding and critical fragment length values compared to the untreated Yarns by 18.9% and 15.1%, respectively. The treatment was less effective for epoxy matrix, for which debonding and critical fragment length values were reduced to a lesser extent, by 3.4% and 3.7%, respectively.
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interfacial adhesion assessment in flax epoxy and in flax vinylester composites by Single Yarn fragmentation test correlation with micro ct analysis
Composites Part A-applied Science and Manufacturing, 2018Co-Authors: Maria Carolina Seghini, Fabienne Touchard, Fabrizio Sarasini, Laurence Chocinskiarnault, David Mellier, Jacopo TirilloAbstract:Abstract Despite the academic interest in using plant fibres as reinforcement in polymer composites to replace glass fibres, the industrial exploitation of resulting composites in semi- or structural applications is still limited. This is mainly due to the poor adhesion at the plant fibre/polymer matrix interface dictated by their surface chemistry and strong hydrophilic behaviour. In the present work, an assessment of the interfacial adhesion at the Yarn scale has been carried out. Fragmentation tests have been performed on flax/epoxy and flax/vinylester Single Yarn composites. High-resolution microtomography has allowed a 3-D reconstruction of the breaking area of the flax Yarn. The flax/epoxy system has shown the lowest values of critical fragment length and interfacial debonding length, and the highest values of IFSS. For both epoxy and vinylester samples, it was found that the breakage of flax has been mainly concentrated in the peripheral zone of the Yarn.
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influence of water on damage and mechanical behaviour of Single hemp Yarn composites
Polymer Testing, 2017Co-Authors: Amelie Perrier, Fabienne Touchard, Laurence Chocinskiarnault, David MellierAbstract:Abstract This study aims to investigate the influence of water ageing on local deformation around a Yarn in a hemp/epoxy composite. Specific Single Yarn composites were manufactured with the Yarn oriented at 90° with respect to the tensile direction and with two types of epoxy resin, one being fully synthetic and the other one partially bio-based. First, a quantification of damage due to the water ageing is realised and photoelasticimetry analysis is used to study the evolution of the state of stress. Then, dumbbell samples with or without water ageing were tested under an optical microscope, and strain fields around the Yarn were measured with the Digital Image Correlation (DIC) technique. The experimental results showed an increase in the measured strain after the water ageing. The local constitutive behaviour of the different constituents of the specimens could be approached by local analyses, and the evolution of the apparent stiffness values are discussed.
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mechanical behaviour analysis of the interface in Single hemp Yarn composites dic measurements and fem calculations
Polymer Testing, 2016Co-Authors: Amelie Perrier, Fabienne Touchard, Laurence Chocinskiarnault, David MellierAbstract:Abstract The present work aims to investigate the local deformation mechanisms around a Yarn in an eco-composite. Different hemp Yarn orientations and two types of epoxy resin were tested. Full-field measurements were realised with the digital image correlation technique on specific Single Yarn composites, either on the face of the specimens, or on the edge. The tensile tests were performed under an optical microscope to give sufficient precision, and a numerical model was developed. The experimental results showed high heterogeneities in strain fields which increase with the applied stress level. The comparison with the underlying microstructure and the numerical model enabled us to study the influence of the Yarn on the mechanical behaviour. The local constitutive behaviour of the different constituents of the specimens could be approached by these analyses. These results constitute a complete and original database on hemp/epoxy interface mechanical behaviour.
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damage mechanisms in hemp fibre woven fabric composite and comparison with glass fibre composite
Polymers & Polymer Composites, 2011Co-Authors: C Onnafous, Fabienne Touchard, Laurence ChocinskiarnaulAbstract:This paper deals with hemp-fibre and glass-fibre woven fabric/epoxy composites. The aim is to analyse damage mechanisms in these composites by comparing three different methods: acoustic emission, microscopic observations and stiffness loss measurement. For acoustic emission (AE), an experimental multi-scale analysis was developed in order to identify the different damage mechanisms. Tensile tests were performed on Single Yarn, neat epoxy resin and composite materials to determine their AE amplitude signatures. A statistical analysis of AE amplitude signals was realised and correlated with microscopic observations. This study has enabled to identify the amplitude and to track, during tensile tests, three types of damage in these composites: matrix cracking, interfacial debonding and reinforcement fracture. It shows the different processes of damage development in natural fibre reinforced composites, in comparison with glass fibre composites. These results were compared to the measured stiffness loss of composites. It allows one to highlight the difficulty to link this mechanical damage parameter with physical AE events.
Jacopo Tirillo - One of the best experts on this subject based on the ideXlab platform.
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Environmentally Friendly Surface Modification Treatment of Flax Fibers by Supercritical Carbon Dioxide
Molecules, 2020Co-Authors: Maria Carolina Seghini, Fabienne Touchard, Jacopo Tirillo, Laurence Chocinski-arnault, Vincent Placet, Camille François, Laurent Plasseraud, Maria Paola Bracciale, Fabrizio SarasiniAbstract:The present work investigates the effects of an environmentally friendly treatment based on supercritical carbon dioxide (scCO2) on the interfacial adhesion of flax fibers with thermoset matrices. In particular, the influence of this green treatment on the mechanical (by Single Yarn tensile test), thermal (by TGA), and chemical (by FT-IR) properties of commercially available flax Yarns was preliminary addressed. Results showed that scCO2 can significantly modify the biochemical composition of flax fibers, by selectively removing lignin and hemicellulose, without altering their thermal stability and, most importantly, their mechanical properties. Single Yarn fragmentation test results highlighted an increased interfacial adhesion after scCO2 treatment, especially for the vinylester matrix, in terms of reduced debonding and critical fragment length values compared to the untreated Yarns by 18.9% and 15.1%, respectively. The treatment was less effective for epoxy matrix, for which debonding and critical fragment length values were reduced to a lesser extent, by 3.4% and 3.7%, respectively.
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interfacial adhesion assessment in flax epoxy and in flax vinylester composites by Single Yarn fragmentation test correlation with micro ct analysis
Composites Part A-applied Science and Manufacturing, 2018Co-Authors: Maria Carolina Seghini, Fabienne Touchard, Fabrizio Sarasini, Laurence Chocinskiarnault, David Mellier, Jacopo TirilloAbstract:Abstract Despite the academic interest in using plant fibres as reinforcement in polymer composites to replace glass fibres, the industrial exploitation of resulting composites in semi- or structural applications is still limited. This is mainly due to the poor adhesion at the plant fibre/polymer matrix interface dictated by their surface chemistry and strong hydrophilic behaviour. In the present work, an assessment of the interfacial adhesion at the Yarn scale has been carried out. Fragmentation tests have been performed on flax/epoxy and flax/vinylester Single Yarn composites. High-resolution microtomography has allowed a 3-D reconstruction of the breaking area of the flax Yarn. The flax/epoxy system has shown the lowest values of critical fragment length and interfacial debonding length, and the highest values of IFSS. For both epoxy and vinylester samples, it was found that the breakage of flax has been mainly concentrated in the peripheral zone of the Yarn.
Fabrizio Sarasini - One of the best experts on this subject based on the ideXlab platform.
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Environmentally Friendly Surface Modification Treatment of Flax Fibers by Supercritical Carbon Dioxide
Molecules, 2020Co-Authors: Maria Carolina Seghini, Fabienne Touchard, Jacopo Tirillo, Laurence Chocinski-arnault, Vincent Placet, Camille François, Laurent Plasseraud, Maria Paola Bracciale, Fabrizio SarasiniAbstract:The present work investigates the effects of an environmentally friendly treatment based on supercritical carbon dioxide (scCO2) on the interfacial adhesion of flax fibers with thermoset matrices. In particular, the influence of this green treatment on the mechanical (by Single Yarn tensile test), thermal (by TGA), and chemical (by FT-IR) properties of commercially available flax Yarns was preliminary addressed. Results showed that scCO2 can significantly modify the biochemical composition of flax fibers, by selectively removing lignin and hemicellulose, without altering their thermal stability and, most importantly, their mechanical properties. Single Yarn fragmentation test results highlighted an increased interfacial adhesion after scCO2 treatment, especially for the vinylester matrix, in terms of reduced debonding and critical fragment length values compared to the untreated Yarns by 18.9% and 15.1%, respectively. The treatment was less effective for epoxy matrix, for which debonding and critical fragment length values were reduced to a lesser extent, by 3.4% and 3.7%, respectively.
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interfacial adhesion assessment in flax epoxy and in flax vinylester composites by Single Yarn fragmentation test correlation with micro ct analysis
Composites Part A-applied Science and Manufacturing, 2018Co-Authors: Maria Carolina Seghini, Fabienne Touchard, Fabrizio Sarasini, Laurence Chocinskiarnault, David Mellier, Jacopo TirilloAbstract:Abstract Despite the academic interest in using plant fibres as reinforcement in polymer composites to replace glass fibres, the industrial exploitation of resulting composites in semi- or structural applications is still limited. This is mainly due to the poor adhesion at the plant fibre/polymer matrix interface dictated by their surface chemistry and strong hydrophilic behaviour. In the present work, an assessment of the interfacial adhesion at the Yarn scale has been carried out. Fragmentation tests have been performed on flax/epoxy and flax/vinylester Single Yarn composites. High-resolution microtomography has allowed a 3-D reconstruction of the breaking area of the flax Yarn. The flax/epoxy system has shown the lowest values of critical fragment length and interfacial debonding length, and the highest values of IFSS. For both epoxy and vinylester samples, it was found that the breakage of flax has been mainly concentrated in the peripheral zone of the Yarn.
Subramaniam Rajan - One of the best experts on this subject based on the ideXlab platform.
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strain rate and gage length effects on tensile behavior of kevlar 49 Single Yarn
Composites Part A-applied Science and Manufacturing, 2012Co-Authors: Barzin Mobasher, Juan Erni, S Bansal, Subramaniam RajanAbstract:Abstract In the present paper, Kevlar® 49 Single Yarns with different gage lengths were tested under both quasi-static loading at a strain rate of 4.2 × 10 −4 s −1 using a MTS load frame and dynamic tensile loading over a strain rate range of 20–100 s −1 using a servo-hydraulic high-rate testing system. The experimental results showed that the material mechanical properties are dependent on gage length and strain rate. Young’s modulus, tensile strength, maximum strain and toughness increase with increasing strain rate under dynamic loading; however the tensile strength decreases with increasing gage length under quasi-static loading. Weibull statistics were used to quantify the degree of variability in Yarn strength at different gage lengths and strain rates. This data was then used to build an analytical model simulating the stress–strain response of Single Yarn under dynamic loading. The model predictions agree reasonably well with the experimental data.
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experimental study and modeling of Single Yarn pull out behavior of kevlar 49 fabric
Composites Part A-applied Science and Manufacturing, 2011Co-Authors: Chote Soranakom, Barzin Mobasher, Subramaniam RajanAbstract:Single Yarn pull-out behavior of Kevlar® 49 fabric with varying lengths and pre-applied transverse tensile forces is studied. Results indicate that both peak pull-out force and energy needed to pull an individual Yarn increase with specimen length and transverse pre-load. An analytical model is used to investigate the frictional shear properties diagram between the orthogonal warp and fill Yarns. Maximum static and dynamic frictional shear strength of contact interfaces of warp and fill Yarns are obtained by fitting the experimental data. The periodic nature of the post-peak behavior of pull-out response is simulated by representing the contact area as a sinusoidal function with a constant period. Finally, a three-dimensional finite element model is used to simulate the Single Yarn pull-out behavior and the results show that pull-out force is significantly influenced by the friction between Yarns and transverse pre-load.
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experimental study of dynamic behavior of kevlar 49 Single Yarn
SEM Annual Conference and Exposition on Experimental and Applied Mechanics 2010, 2011Co-Authors: Deju Zhu, Barzin Mobasher, Subramaniam RajanAbstract:Aramid and other high strength fibers and fabrics have been studied extensively due to their application in a wide range of products such as bullet-proof vests, confinement chambers for jet engines, cut-resistant gloves et al. These applications have created a demand for numerical modeling of the fabrics and more in depth information about the behavior of fibrous materials and Yarns. Manufacturers of yams usually provide quasi-static tensile strength for the Single fiber form of the material. However, this information cannot be scaled up directly for a Yarn consisting of many fibers. Also, the strain rate at which this information is obtained is not in the same order of magnitude as the strain rates observed in ballistic applications. In this study, Kevlar 49® Single Yarn was tested in tension within a strain rate range of 20 to 100 s-1 using a high speed servo-hydraulic testing system. The failure behavior of test specimen was recorded by a high speed digital camera. Results were used to investigate the strain rate effect on the dynamic material properties in terms of Young’s modulus, tensile strength, maximum strain and toughness. The dependence of dynamic material properties on the strain rate was discussed.