The Experts below are selected from a list of 2262 Experts worldwide ranked by ideXlab platform

Janice M. Dulieu-barton - One of the best experts on this subject based on the ideXlab platform.

  • Thermoelastic stress analysis of damage mechanisms in composite materials
    Composites Part A: Applied Science and Manufacturing, 2010
    Co-Authors: T.r. Emery, Janice M. Dulieu-barton
    Abstract:

    A methodology for the application of Thermoelastic Stress Analysis (TSA) in damage studies of glass reinforced polymers is established. Test specimens have been designed to promote certain damage types and the methodology applied to each. It is shown that a TSA approach can evaluate Fibre Breakage, matrix cracking and delamination damage. Metrics are established based on calibrated strain data obtained from the TSA. It is shown that these can be used to assess the condition of a component throughout its fatigue life.

  • Prediction of fatigue life in composite materials using thermoelastic stress analysis
    2008
    Co-Authors: Janice M. Dulieu-barton, Trystan Emery
    Abstract:

    Thermoelastic Stress Analysis (TSA) is developed to provide a prediction of fatigue life in glass reinforced polymers. A test specimens has been designed to promote cracking and a methodology is defined that allows the measurement of the strain in the damaged region. It is shown that a TSA approach can evaluate Fibre Breakage, matrix cracking and delamination damage. A strain based metric is established based on calibrated data obtained from the TSA, which can be used to assess the condition of a component throughout its fatigue life.

Kristiina Oksman - One of the best experts on this subject based on the ideXlab platform.

  • pelletized cellulose Fibres used in twin screw extrusion for biocomposite manufacturing Fibre Breakage and dispersion
    Composites Part A-applied Science and Manufacturing, 2018
    Co-Authors: Maiju Hietala, Kristiina Oksman
    Abstract:

    Abstract Pelletizing is effective in compacting cellulose Fibres, but it also causes Fibre Breakage and poor dispersion due to increased hydrogen bonding. This study investigated whether Fibre dispersion and length could be improved by the addition of a lubricant, a commonly used composite processing aid, into cellulose pellets, or by using pelletized Fibres that have not been completely dried to reduce hydrogen bonding. Cellulose pellets with different lubricant and moisture contents were prepared and compounded using twin-screw extrusion with polypropylene with 5 wt% Fibre and 50 wt% Fibre contents. The Fibre dispersion, morphology and mechanical properties of the prepared composites were analysed. Dispersion and composite strength were improved with the addition of 4–6 wt% of lubricant while moisture had a negative effect on both properties. This study demonstrated that pelletization in the presence of a lubricant is a promising way to compact cellulose Fibres and enable their continuous processing into biocomposites with improved mechanical properties.

  • The influence of Fibre microstructure on Fibre Breakage and mechanical properties of natural Fibre reinforced polypropylene
    Composites Science and Technology, 2009
    Co-Authors: Kristiina Oksman, Aji P. Mathew, Runar Långström, Birgitha Nyström, Kuruvilla Joseph
    Abstract:

    The aim of the study was to investigate the influence of Fibre morphology of different natural Fibres on the composites mechanical properties and on the Fibre Breakage due to extrusion process. The composite materials were manufactured using LTF (long Fibre thermoplastic) extrusion and compression moulding and the used Fibres were sisal, banana, jute and flax, and the matrix was a polypropylene. The results showed that sisal composites had the best impact properties and the longest Fibres after the extrusion. Generally, the composites flexural stiffness was increased with increased Fibre content for all Fibres, being highest for flax composites. The flexural strength was not affected by the addition of Fibres because of the low compatibility. The addition of 2 wt.% maleated polypropylene significantly improved the composites properties. Unlike the other three Fibres, flax Fibres were separated into individual elementary Fibres during the process due to enzymatic retting and low lignin content.

Bruno Vergnes - One of the best experts on this subject based on the ideXlab platform.

  • A matricial approach of Fibre Breakage in twin-screw extrusion of glass Fibres reinforced thermoplastics
    Composites Part A: Applied Science and Manufacturing, 2013
    Co-Authors: Audrey Durin, Pascal De Micheli, Julien Ville, Funda Inceoglu, Rudy Valette, Bruno Vergnes
    Abstract:

    Limiting Fibre Breakage during composite processing is a crucial issue. The purpose of this paper is to predict the evolution of the Fibre-length distribution along a twin-screw extruder. This approach relies on using a fragmentation matrix to describe changes in the Fibre-length distribution. The flow parameters in the screw elements are obtained using the simulation software Ludovic®. Evolution of an initial Fibre-length distribution for several processing conditions was computed and the results were compared with experimental values. The computation gives satisfying results, even though more comparisons with experiments would be necessary.

M. O. W. Richardson - One of the best experts on this subject based on the ideXlab platform.

  • Low velocity response of a complex geometry pultruded glass/polyester composite
    Journal of Materials Science, 1999
    Co-Authors: M. Wisheart, M. O. W. Richardson
    Abstract:

    This paper describes an investigation into the low velocity impact response on complex geometry sections taken from a pultruded glass/polyester product. The empirical impact behaviour of the system was evaluated using instrumented falling weight impact testing (IFWI) in conjunction with ultrasonic C-Scan, optical microscopy and thermal deply techniques to detect delamination, matrix cracking, and Fibre Breakage.

  • Low velocity response of simple geometry pultruded glass/polyester composite
    Journal of Materials Science, 1999
    Co-Authors: M. Wisheart, M. O. W. Richardson
    Abstract:

    This paper describes an investigation into the low velocity impact response of relatively simple geometry coupons taken from a pultruded glass/polyester product. The pultruded lay-up is a typical three ply design – a unidirectional Fibre ply sandwiched between two continuous filament mat plies. By employing a simple geometry the impact response under transverse and longitudinal bending, and shear loading are considered. Impact tests from low energy through to final failure were conducted using the instrumented falling weight impact test technique. Through a detailed analysis involving ultrasonic C-scan, optical microscopy, and thermal deply all the major damage modes (delamination, Fibre Breakage and matrix cracking) were related to the force-deflection responses.

T.r. Emery - One of the best experts on this subject based on the ideXlab platform.

  • Thermoelastic stress analysis of damage mechanisms in composite materials
    Composites Part A: Applied Science and Manufacturing, 2010
    Co-Authors: T.r. Emery, Janice M. Dulieu-barton
    Abstract:

    A methodology for the application of Thermoelastic Stress Analysis (TSA) in damage studies of glass reinforced polymers is established. Test specimens have been designed to promote certain damage types and the methodology applied to each. It is shown that a TSA approach can evaluate Fibre Breakage, matrix cracking and delamination damage. Metrics are established based on calibrated strain data obtained from the TSA. It is shown that these can be used to assess the condition of a component throughout its fatigue life.