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Mchael R Wisnom - One of the best experts on this subject based on the ideXlab platform.

  • high performance quasi isotropic thin ply carbon Glass hybrid composites with pseudo ductile behaviour loaded off axis
    Composite Structures, 2020
    Co-Authors: Mohamad Fotouhi, Meisam Jalalvand, Milad Saeedifar, Bill Xiao, Mchael R Wisnom
    Abstract:

    The aim of this work was to investigate the effect of loading angle variation on the pseudo-ductility of quasi-isotropic (QI) hybrid composite Laminates. Previously, hybrids of thin-ply carbon fibres and standard Glass fibres were found to have an excellent pseudo-ductile behaviour both in unidirectional (UD) and QI configurations when subjected to axial tension in the fibres’ orientations. In this work, the QI Laminates, with 60° intervals, have been subjected to a quasi-static tensile load at various off-axis orientations – i.e. 5°, 10° and 20°. The QI hybrid composites were made by sandwiching a QI T300-carbon Laminate between the two halves of a QI S-Glass Laminate. The results showed a pseudo-ductile behaviour with a linear elastic part and a desirable plateau for all the loading directions, however the pseudo-ductile strain decreases when increasing the off-axis angle. Comparing the 20° off-axis with the other cases, there was more active matrix cracking damage before fragmentation in the 20° off-axis plies and it failed earlier than the other samples. Acoustic emission (AE) results confirmed this, with more matrix cracking related AE signals in the 20° off-axis case compared to the other configurations.

  • high performance quasi isotropic thin ply carbon Glass hybrid composites with pseudo ductile behaviour in all fibre orientations
    Composites Science and Technology, 2017
    Co-Authors: Mohamad Fotouhi, Meisam Jalalvand, Mchael R Wisnom
    Abstract:

    This study exploits the potential of thin-ply carbon/Glass hybrid Laminates to generate high performance Quasi-Isotropic (QI) composite plates that show pseudo-ductility in all fibre orientations under tensile loading, overcoming the inherent brittleness of conventional composites. Two types of QI lay-ups with 45° and 60° intervals, i.e. [45/90/-45/0] and [60/-60/0], were used to fabricate novel architectures of a QI T300-carbon Laminate sandwiched between the two halves of a QI S-Glass Laminate. The fabricated plates were then loaded in all their fibre orientations. The Laminates were designed by choosing an appropriate ratio of the carbon thickness to the Laminate thickness using a robust analytical damage mode map. The experimental results verified the analytical predictions and showed a desirable pseudo-ductile failure in all the fibre orientations. Microscope images taken through the Laminates thickness showed fragmentations (fibre fractures in the carbon layer) appearing only in the 0° carbon plies. A hybrid effect was observed, with an increase in strain and stress to failure of the carbon fibres, which was found to be dependent on the stiffness of the plies separating the 0° carbon plies and the plies adjacent to the 0° carbon plies. Altering the stacking sequence changes the stiffness of the separator and adjacent plies, therefore, leads to changes in the pseudo-ductile characteristics such as the initiation and final failure strains.

Mohamad Fotouhi - One of the best experts on this subject based on the ideXlab platform.

  • high performance quasi isotropic thin ply carbon Glass hybrid composites with pseudo ductile behaviour loaded off axis
    Composite Structures, 2020
    Co-Authors: Mohamad Fotouhi, Meisam Jalalvand, Milad Saeedifar, Bill Xiao, Mchael R Wisnom
    Abstract:

    The aim of this work was to investigate the effect of loading angle variation on the pseudo-ductility of quasi-isotropic (QI) hybrid composite Laminates. Previously, hybrids of thin-ply carbon fibres and standard Glass fibres were found to have an excellent pseudo-ductile behaviour both in unidirectional (UD) and QI configurations when subjected to axial tension in the fibres’ orientations. In this work, the QI Laminates, with 60° intervals, have been subjected to a quasi-static tensile load at various off-axis orientations – i.e. 5°, 10° and 20°. The QI hybrid composites were made by sandwiching a QI T300-carbon Laminate between the two halves of a QI S-Glass Laminate. The results showed a pseudo-ductile behaviour with a linear elastic part and a desirable plateau for all the loading directions, however the pseudo-ductile strain decreases when increasing the off-axis angle. Comparing the 20° off-axis with the other cases, there was more active matrix cracking damage before fragmentation in the 20° off-axis plies and it failed earlier than the other samples. Acoustic emission (AE) results confirmed this, with more matrix cracking related AE signals in the 20° off-axis case compared to the other configurations.

  • thin ply carbon Glass hybrid Laminates to activate new damage mechanisms under indentation
    18th European Conference on Composite Materials ECCM 2018, 2018
    Co-Authors: Mohamad Fotouhi, Meisam Jalalvand, Alessia Prato
    Abstract:

    Low velocity impacts on composite Laminates can cause a significant amount of delamination that is often referred to as barely visible impact damage (BVID). This damage can cause significant degradation of structural properties, especially the compressive strength after impact. The aim of this work was to utilise thin ply carbon/Glass hybrid Laminates to activate new types of damage mechanisms under indentation (quasi-static impact) that are more gradual and easier to detect. Therefore, 3 different types of hybrid composite plates fabricated from novel hybrid architectures of thin ply high modulus carbon (HS40) and standard thickness S-Glass Laminates were investigated. For comparison, a Laminate containing only S-Glass plies was investigated as well. The investigated specimens were interrupted at different load-levels and a detailed assessment of the damage evolution was carried out using X-ray Computed Tomography (CT). For all the hybrid configurations, a larger damage area was observed mostly under the indenter and the delaminations were smaller in the middle plies compared to the upper plies. In contrast, for the Glass Laminates the delaminations were larger in the middle plies compared to the upper plies. For the hybrid Laminates, the percentage of the first load drop in the global load–displacement curves was lower whereas the percentage of the stiffness reduction after the first load drop was higher, compared to the Glass Laminate. Overall the hybrid results showed some different damage mechanisms, i.e. carbon ply fibre fracture and delamination under the indenter, with a gradual failure behaviour and less damage to the inner layers. The degradation mechanisms were visually detectable from the indented face from the early stage of the loading for some of the hybrid configurations, which can act as impact damage indicator.

  • high performance quasi isotropic thin ply carbon Glass hybrid composites with pseudo ductile behaviour in all fibre orientations
    Composites Science and Technology, 2017
    Co-Authors: Mohamad Fotouhi, Meisam Jalalvand, Mchael R Wisnom
    Abstract:

    This study exploits the potential of thin-ply carbon/Glass hybrid Laminates to generate high performance Quasi-Isotropic (QI) composite plates that show pseudo-ductility in all fibre orientations under tensile loading, overcoming the inherent brittleness of conventional composites. Two types of QI lay-ups with 45° and 60° intervals, i.e. [45/90/-45/0] and [60/-60/0], were used to fabricate novel architectures of a QI T300-carbon Laminate sandwiched between the two halves of a QI S-Glass Laminate. The fabricated plates were then loaded in all their fibre orientations. The Laminates were designed by choosing an appropriate ratio of the carbon thickness to the Laminate thickness using a robust analytical damage mode map. The experimental results verified the analytical predictions and showed a desirable pseudo-ductile failure in all the fibre orientations. Microscope images taken through the Laminates thickness showed fragmentations (fibre fractures in the carbon layer) appearing only in the 0° carbon plies. A hybrid effect was observed, with an increase in strain and stress to failure of the carbon fibres, which was found to be dependent on the stiffness of the plies separating the 0° carbon plies and the plies adjacent to the 0° carbon plies. Altering the stacking sequence changes the stiffness of the separator and adjacent plies, therefore, leads to changes in the pseudo-ductile characteristics such as the initiation and final failure strains.

Meisam Jalalvand - One of the best experts on this subject based on the ideXlab platform.

  • high performance quasi isotropic thin ply carbon Glass hybrid composites with pseudo ductile behaviour loaded off axis
    Composite Structures, 2020
    Co-Authors: Mohamad Fotouhi, Meisam Jalalvand, Milad Saeedifar, Bill Xiao, Mchael R Wisnom
    Abstract:

    The aim of this work was to investigate the effect of loading angle variation on the pseudo-ductility of quasi-isotropic (QI) hybrid composite Laminates. Previously, hybrids of thin-ply carbon fibres and standard Glass fibres were found to have an excellent pseudo-ductile behaviour both in unidirectional (UD) and QI configurations when subjected to axial tension in the fibres’ orientations. In this work, the QI Laminates, with 60° intervals, have been subjected to a quasi-static tensile load at various off-axis orientations – i.e. 5°, 10° and 20°. The QI hybrid composites were made by sandwiching a QI T300-carbon Laminate between the two halves of a QI S-Glass Laminate. The results showed a pseudo-ductile behaviour with a linear elastic part and a desirable plateau for all the loading directions, however the pseudo-ductile strain decreases when increasing the off-axis angle. Comparing the 20° off-axis with the other cases, there was more active matrix cracking damage before fragmentation in the 20° off-axis plies and it failed earlier than the other samples. Acoustic emission (AE) results confirmed this, with more matrix cracking related AE signals in the 20° off-axis case compared to the other configurations.

  • thin ply carbon Glass hybrid Laminates to activate new damage mechanisms under indentation
    18th European Conference on Composite Materials ECCM 2018, 2018
    Co-Authors: Mohamad Fotouhi, Meisam Jalalvand, Alessia Prato
    Abstract:

    Low velocity impacts on composite Laminates can cause a significant amount of delamination that is often referred to as barely visible impact damage (BVID). This damage can cause significant degradation of structural properties, especially the compressive strength after impact. The aim of this work was to utilise thin ply carbon/Glass hybrid Laminates to activate new types of damage mechanisms under indentation (quasi-static impact) that are more gradual and easier to detect. Therefore, 3 different types of hybrid composite plates fabricated from novel hybrid architectures of thin ply high modulus carbon (HS40) and standard thickness S-Glass Laminates were investigated. For comparison, a Laminate containing only S-Glass plies was investigated as well. The investigated specimens were interrupted at different load-levels and a detailed assessment of the damage evolution was carried out using X-ray Computed Tomography (CT). For all the hybrid configurations, a larger damage area was observed mostly under the indenter and the delaminations were smaller in the middle plies compared to the upper plies. In contrast, for the Glass Laminates the delaminations were larger in the middle plies compared to the upper plies. For the hybrid Laminates, the percentage of the first load drop in the global load–displacement curves was lower whereas the percentage of the stiffness reduction after the first load drop was higher, compared to the Glass Laminate. Overall the hybrid results showed some different damage mechanisms, i.e. carbon ply fibre fracture and delamination under the indenter, with a gradual failure behaviour and less damage to the inner layers. The degradation mechanisms were visually detectable from the indented face from the early stage of the loading for some of the hybrid configurations, which can act as impact damage indicator.

  • high performance quasi isotropic thin ply carbon Glass hybrid composites with pseudo ductile behaviour in all fibre orientations
    Composites Science and Technology, 2017
    Co-Authors: Mohamad Fotouhi, Meisam Jalalvand, Mchael R Wisnom
    Abstract:

    This study exploits the potential of thin-ply carbon/Glass hybrid Laminates to generate high performance Quasi-Isotropic (QI) composite plates that show pseudo-ductility in all fibre orientations under tensile loading, overcoming the inherent brittleness of conventional composites. Two types of QI lay-ups with 45° and 60° intervals, i.e. [45/90/-45/0] and [60/-60/0], were used to fabricate novel architectures of a QI T300-carbon Laminate sandwiched between the two halves of a QI S-Glass Laminate. The fabricated plates were then loaded in all their fibre orientations. The Laminates were designed by choosing an appropriate ratio of the carbon thickness to the Laminate thickness using a robust analytical damage mode map. The experimental results verified the analytical predictions and showed a desirable pseudo-ductile failure in all the fibre orientations. Microscope images taken through the Laminates thickness showed fragmentations (fibre fractures in the carbon layer) appearing only in the 0° carbon plies. A hybrid effect was observed, with an increase in strain and stress to failure of the carbon fibres, which was found to be dependent on the stiffness of the plies separating the 0° carbon plies and the plies adjacent to the 0° carbon plies. Altering the stacking sequence changes the stiffness of the separator and adjacent plies, therefore, leads to changes in the pseudo-ductile characteristics such as the initiation and final failure strains.

Bill Xiao - One of the best experts on this subject based on the ideXlab platform.

  • high performance quasi isotropic thin ply carbon Glass hybrid composites with pseudo ductile behaviour loaded off axis
    Composite Structures, 2020
    Co-Authors: Mohamad Fotouhi, Meisam Jalalvand, Milad Saeedifar, Bill Xiao, Mchael R Wisnom
    Abstract:

    The aim of this work was to investigate the effect of loading angle variation on the pseudo-ductility of quasi-isotropic (QI) hybrid composite Laminates. Previously, hybrids of thin-ply carbon fibres and standard Glass fibres were found to have an excellent pseudo-ductile behaviour both in unidirectional (UD) and QI configurations when subjected to axial tension in the fibres’ orientations. In this work, the QI Laminates, with 60° intervals, have been subjected to a quasi-static tensile load at various off-axis orientations – i.e. 5°, 10° and 20°. The QI hybrid composites were made by sandwiching a QI T300-carbon Laminate between the two halves of a QI S-Glass Laminate. The results showed a pseudo-ductile behaviour with a linear elastic part and a desirable plateau for all the loading directions, however the pseudo-ductile strain decreases when increasing the off-axis angle. Comparing the 20° off-axis with the other cases, there was more active matrix cracking damage before fragmentation in the 20° off-axis plies and it failed earlier than the other samples. Acoustic emission (AE) results confirmed this, with more matrix cracking related AE signals in the 20° off-axis case compared to the other configurations.

Milad Saeedifar - One of the best experts on this subject based on the ideXlab platform.

  • high performance quasi isotropic thin ply carbon Glass hybrid composites with pseudo ductile behaviour loaded off axis
    Composite Structures, 2020
    Co-Authors: Mohamad Fotouhi, Meisam Jalalvand, Milad Saeedifar, Bill Xiao, Mchael R Wisnom
    Abstract:

    The aim of this work was to investigate the effect of loading angle variation on the pseudo-ductility of quasi-isotropic (QI) hybrid composite Laminates. Previously, hybrids of thin-ply carbon fibres and standard Glass fibres were found to have an excellent pseudo-ductile behaviour both in unidirectional (UD) and QI configurations when subjected to axial tension in the fibres’ orientations. In this work, the QI Laminates, with 60° intervals, have been subjected to a quasi-static tensile load at various off-axis orientations – i.e. 5°, 10° and 20°. The QI hybrid composites were made by sandwiching a QI T300-carbon Laminate between the two halves of a QI S-Glass Laminate. The results showed a pseudo-ductile behaviour with a linear elastic part and a desirable plateau for all the loading directions, however the pseudo-ductile strain decreases when increasing the off-axis angle. Comparing the 20° off-axis with the other cases, there was more active matrix cracking damage before fragmentation in the 20° off-axis plies and it failed earlier than the other samples. Acoustic emission (AE) results confirmed this, with more matrix cracking related AE signals in the 20° off-axis case compared to the other configurations.