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Michael A. Mccarthy - One of the best experts on this subject based on the ideXlab platform.

  • insights into complex rheological behaviour of carbon Fibre peek from a novel numerical methodology incorporating Fibre Friction and melt viscosity
    Composite Structures, 2018
    Co-Authors: Anne Deignan, Lukasz Figiel, Michael A. Mccarthy
    Abstract:

    Abstract A recent rheological study of carbon-Fibre-reinforced PEEK (CF/PEEK) demonstrated highly complex behaviour, involving phenomenological differences at low and high strain rates. To explain the behaviour, it was hypothesised that CF/PEEK responds as a yield-stress fluid at low strain rates, with boundary-lubricated, Fibre-Fibre Friction determining the viscosity, and as a viscous fluid at high strain rates, with polymer melt viscosity dominating the response. In this paper, a novel finite-element methodology, incorporating Fibre Friction and melt viscosity in the same model, is employed to study this hypothesis. Two-Fibre models investigate how Fibre Friction and melt viscosity combine to produce an overall composite viscosity. Representative-volume-element (RVE) models examine multi-Fibre/melt response, and demonstrate that inclusion of Fibre Friction produces the observed yield-stress behaviour at low strain rates, and viscous behaviour at high strain rates. Another phenomenon which affects rheological measurements of such composites is shear banding in the sample, which occurs in the yield-stress regime. This effect is demonstrated in the models, and analysis of load transfer between Fibres and melt explains how it arises, and how it leads to diminished values of measured viscosity. The results pave the way for improved process models for high-throughput manufacturing processes such as Automated Tape Placement.

  • Insights into complex rheological behaviour of carbon Fibre/PEEK from a novel numerical methodology incorporating Fibre Friction and melt viscosity
    Composite Structures, 2018
    Co-Authors: Anne Deignan, Lukasz Figiel, Michael A. Mccarthy
    Abstract:

    Abstract A recent rheological study of carbon-Fibre-reinforced PEEK (CF/PEEK) demonstrated highly complex behaviour, involving phenomenological differences at low and high strain rates. To explain the behaviour, it was hypothesised that CF/PEEK responds as a yield-stress fluid at low strain rates, with boundary-lubricated, Fibre-Fibre Friction determining the viscosity, and as a viscous fluid at high strain rates, with polymer melt viscosity dominating the response. In this paper, a novel finite-element methodology, incorporating Fibre Friction and melt viscosity in the same model, is employed to study this hypothesis. Two-Fibre models investigate how Fibre Friction and melt viscosity combine to produce an overall composite viscosity. Representative-volume-element (RVE) models examine multi-Fibre/melt response, and demonstrate that inclusion of Fibre Friction produces the observed yield-stress behaviour at low strain rates, and viscous behaviour at high strain rates. Another phenomenon which affects rheological measurements of such composites is shear banding in the sample, which occurs in the yield-stress regime. This effect is demonstrated in the models, and analysis of load transfer between Fibres and melt explains how it arises, and how it leads to diminished values of measured viscosity. The results pave the way for improved process models for high-throughput manufacturing processes such as Automated Tape Placement.

Anne Deignan - One of the best experts on this subject based on the ideXlab platform.

  • insights into complex rheological behaviour of carbon Fibre peek from a novel numerical methodology incorporating Fibre Friction and melt viscosity
    Composite Structures, 2018
    Co-Authors: Anne Deignan, Lukasz Figiel, Michael A. Mccarthy
    Abstract:

    Abstract A recent rheological study of carbon-Fibre-reinforced PEEK (CF/PEEK) demonstrated highly complex behaviour, involving phenomenological differences at low and high strain rates. To explain the behaviour, it was hypothesised that CF/PEEK responds as a yield-stress fluid at low strain rates, with boundary-lubricated, Fibre-Fibre Friction determining the viscosity, and as a viscous fluid at high strain rates, with polymer melt viscosity dominating the response. In this paper, a novel finite-element methodology, incorporating Fibre Friction and melt viscosity in the same model, is employed to study this hypothesis. Two-Fibre models investigate how Fibre Friction and melt viscosity combine to produce an overall composite viscosity. Representative-volume-element (RVE) models examine multi-Fibre/melt response, and demonstrate that inclusion of Fibre Friction produces the observed yield-stress behaviour at low strain rates, and viscous behaviour at high strain rates. Another phenomenon which affects rheological measurements of such composites is shear banding in the sample, which occurs in the yield-stress regime. This effect is demonstrated in the models, and analysis of load transfer between Fibres and melt explains how it arises, and how it leads to diminished values of measured viscosity. The results pave the way for improved process models for high-throughput manufacturing processes such as Automated Tape Placement.

  • Insights into complex rheological behaviour of carbon Fibre/PEEK from a novel numerical methodology incorporating Fibre Friction and melt viscosity
    Composite Structures, 2018
    Co-Authors: Anne Deignan, Lukasz Figiel, Michael A. Mccarthy
    Abstract:

    Abstract A recent rheological study of carbon-Fibre-reinforced PEEK (CF/PEEK) demonstrated highly complex behaviour, involving phenomenological differences at low and high strain rates. To explain the behaviour, it was hypothesised that CF/PEEK responds as a yield-stress fluid at low strain rates, with boundary-lubricated, Fibre-Fibre Friction determining the viscosity, and as a viscous fluid at high strain rates, with polymer melt viscosity dominating the response. In this paper, a novel finite-element methodology, incorporating Fibre Friction and melt viscosity in the same model, is employed to study this hypothesis. Two-Fibre models investigate how Fibre Friction and melt viscosity combine to produce an overall composite viscosity. Representative-volume-element (RVE) models examine multi-Fibre/melt response, and demonstrate that inclusion of Fibre Friction produces the observed yield-stress behaviour at low strain rates, and viscous behaviour at high strain rates. Another phenomenon which affects rheological measurements of such composites is shear banding in the sample, which occurs in the yield-stress regime. This effect is demonstrated in the models, and analysis of load transfer between Fibres and melt explains how it arises, and how it leads to diminished values of measured viscosity. The results pave the way for improved process models for high-throughput manufacturing processes such as Automated Tape Placement.

P Potluri - One of the best experts on this subject based on the ideXlab platform.

  • effects of inter tow angle and tow size on carbon Fibre Friction
    Composites Part A-applied Science and Manufacturing, 2014
    Co-Authors: Nilanjan Das Chakladar, Parthasarathi Mandal, P Potluri
    Abstract:

    Friction plays an important role in the processing behaviour of fabrics or prepregs into geometries that require significant inter-ply and intra-ply movements. In previous studies, coefficient of Friction is generally assumed to be constant. This paper presents a detailed experimental investigation of the Frictional behaviour of carbon Fibres at meso-scale. The inter-tow angle was found to have a significant effect on the tow Friction when the Fibres are parallel; whereas the effect of tow size was marginal. A numerical model was developed to investigate inter-filament Friction from tow Friction using finite element analysis. The filament-to-pulley Friction was found to have a significant effect on the overall load–displacement behaviour, unlike the filament-to-filament Friction. A range of intra-tow filament-to-filament Friction coefficient was also indicated within which the inter-filament slippage began.

Lukasz Figiel - One of the best experts on this subject based on the ideXlab platform.

  • insights into complex rheological behaviour of carbon Fibre peek from a novel numerical methodology incorporating Fibre Friction and melt viscosity
    Composite Structures, 2018
    Co-Authors: Anne Deignan, Lukasz Figiel, Michael A. Mccarthy
    Abstract:

    Abstract A recent rheological study of carbon-Fibre-reinforced PEEK (CF/PEEK) demonstrated highly complex behaviour, involving phenomenological differences at low and high strain rates. To explain the behaviour, it was hypothesised that CF/PEEK responds as a yield-stress fluid at low strain rates, with boundary-lubricated, Fibre-Fibre Friction determining the viscosity, and as a viscous fluid at high strain rates, with polymer melt viscosity dominating the response. In this paper, a novel finite-element methodology, incorporating Fibre Friction and melt viscosity in the same model, is employed to study this hypothesis. Two-Fibre models investigate how Fibre Friction and melt viscosity combine to produce an overall composite viscosity. Representative-volume-element (RVE) models examine multi-Fibre/melt response, and demonstrate that inclusion of Fibre Friction produces the observed yield-stress behaviour at low strain rates, and viscous behaviour at high strain rates. Another phenomenon which affects rheological measurements of such composites is shear banding in the sample, which occurs in the yield-stress regime. This effect is demonstrated in the models, and analysis of load transfer between Fibres and melt explains how it arises, and how it leads to diminished values of measured viscosity. The results pave the way for improved process models for high-throughput manufacturing processes such as Automated Tape Placement.

  • Insights into complex rheological behaviour of carbon Fibre/PEEK from a novel numerical methodology incorporating Fibre Friction and melt viscosity
    Composite Structures, 2018
    Co-Authors: Anne Deignan, Lukasz Figiel, Michael A. Mccarthy
    Abstract:

    Abstract A recent rheological study of carbon-Fibre-reinforced PEEK (CF/PEEK) demonstrated highly complex behaviour, involving phenomenological differences at low and high strain rates. To explain the behaviour, it was hypothesised that CF/PEEK responds as a yield-stress fluid at low strain rates, with boundary-lubricated, Fibre-Fibre Friction determining the viscosity, and as a viscous fluid at high strain rates, with polymer melt viscosity dominating the response. In this paper, a novel finite-element methodology, incorporating Fibre Friction and melt viscosity in the same model, is employed to study this hypothesis. Two-Fibre models investigate how Fibre Friction and melt viscosity combine to produce an overall composite viscosity. Representative-volume-element (RVE) models examine multi-Fibre/melt response, and demonstrate that inclusion of Fibre Friction produces the observed yield-stress behaviour at low strain rates, and viscous behaviour at high strain rates. Another phenomenon which affects rheological measurements of such composites is shear banding in the sample, which occurs in the yield-stress regime. This effect is demonstrated in the models, and analysis of load transfer between Fibres and melt explains how it arises, and how it leads to diminished values of measured viscosity. The results pave the way for improved process models for high-throughput manufacturing processes such as Automated Tape Placement.

Shadpour Mallakpour - One of the best experts on this subject based on the ideXlab platform.

  • A novel durable hydrophobic surface coating of poly(lactic acid) fabric by pulsed plasma polymerization
    Progress in Organic Coatings, 2010
    Co-Authors: Akbar Khoddami, Ozan Avinc, Shadpour Mallakpour
    Abstract:

    Effective finishing on poly(lactic acid) (PLA) Fibres could be difficult due to its low melting point. Traditional fluorocarbon application technology (pad, dry, and cure at high temperature) on poly(ethylene terephthalate) and PLA Fibres fabrics was compared with a novel plasma polymerization technique which was performed on both fabrics. Liquid repellency properties of both mentioned fabrics, before and after washing were evaluated. Fabric mechanical properties were compared by measuring bursting strength and fabric hand. The results indicate that, in general, the plasma process imparted better fabric handle and overall repellency, particularly with regard to low temperature re-orientation. Furthermore, by adding a proper softener, the inter-Fibre Friction was reduced and better elastic recovery was achieved.