Uncovering the fatigue damage initiation and progression in uni-directional non-crimp fabric reinforced polyester composite

Kristine M. Jespersen, Jens A. Glud, Jens Zangenberg, Atsushi Hosoi, Hiroyuki Kawada, Lars P. Mikkelsen

    Research output: Contribution to journalArticle

    5 Citations (Scopus)

    Abstract

    The current work studies the fatigue damage initiation and progression in a quasi-unidirectional non-crimp fabric based fibre composite used for wind turbine blades. This is done by combining in situ transilluminated white light imagining (TWLI) with ex-situ X-ray computed tomography (CT) experiments along with tension clamp X-ray CT experiments. TWLI is used to monitor the off-axis cracks in the thin supporting backing fibre bundles present in quasi-UD composites, and a crack counting algorithm is applied to automatically count the cracks in images obtained in situ during fatigue testing. It is found that off-axis cracks not only initiate at the specimen edges but also at isolated locations inside the specimen, which could be related to the microstructural features. In addition, a clear effect of strain level on the measured off-axis crack density is observed. From the X-ray CT experiments, it is found that the UD fibre fractures initiate and progress from regions where the off-axis backing fibre bundles are ‘in contact’ with a UD fibre bundle. Damage is seen to first initiate at a cross-over region of the backing fibre bundles, and later at a region with only one backing fibre bundle. In addition, applying tension to the specimen during X-ray CT scanning is found to reveal additional UD fibre fractures that are not visible in scans performed the unloaded state. With load applied, a significant number of UD fibre fractures were observed earlier in the fatigue life than expected. Based on the observations of the study a damage progression scheme is presented for quasi-UD fibre composites.

    Original languageEnglish
    Pages (from-to)481-497
    Number of pages17
    JournalComposites Part A: Applied Science and Manufacturing
    Volume109
    DOIs
    Publication statusPublished - 2018 Jun 1

    Fingerprint

    Polyesters
    Fatigue damage
    Fibers
    Composite materials
    Tomography
    Cracks
    X rays
    Fatigue testing
    Experiments
    Clamping devices
    Wind turbines
    Turbomachine blades
    Fatigue of materials
    Scanning

    Keywords

    • A. Glass fibres
    • A. Polymer matrix composites (PMCs)
    • B. Fracture
    • D. Non-destructive testing

    ASJC Scopus subject areas

    • Ceramics and Composites
    • Mechanics of Materials

    Cite this

    Uncovering the fatigue damage initiation and progression in uni-directional non-crimp fabric reinforced polyester composite. / Jespersen, Kristine M.; Glud, Jens A.; Zangenberg, Jens; Hosoi, Atsushi; Kawada, Hiroyuki; Mikkelsen, Lars P.

    In: Composites Part A: Applied Science and Manufacturing, Vol. 109, 01.06.2018, p. 481-497.

    Research output: Contribution to journalArticle

    @article{681060772546423dbf7bfbab36b0c9b4,
    title = "Uncovering the fatigue damage initiation and progression in uni-directional non-crimp fabric reinforced polyester composite",
    abstract = "The current work studies the fatigue damage initiation and progression in a quasi-unidirectional non-crimp fabric based fibre composite used for wind turbine blades. This is done by combining in situ transilluminated white light imagining (TWLI) with ex-situ X-ray computed tomography (CT) experiments along with tension clamp X-ray CT experiments. TWLI is used to monitor the off-axis cracks in the thin supporting backing fibre bundles present in quasi-UD composites, and a crack counting algorithm is applied to automatically count the cracks in images obtained in situ during fatigue testing. It is found that off-axis cracks not only initiate at the specimen edges but also at isolated locations inside the specimen, which could be related to the microstructural features. In addition, a clear effect of strain level on the measured off-axis crack density is observed. From the X-ray CT experiments, it is found that the UD fibre fractures initiate and progress from regions where the off-axis backing fibre bundles are ‘in contact’ with a UD fibre bundle. Damage is seen to first initiate at a cross-over region of the backing fibre bundles, and later at a region with only one backing fibre bundle. In addition, applying tension to the specimen during X-ray CT scanning is found to reveal additional UD fibre fractures that are not visible in scans performed the unloaded state. With load applied, a significant number of UD fibre fractures were observed earlier in the fatigue life than expected. Based on the observations of the study a damage progression scheme is presented for quasi-UD fibre composites.",
    keywords = "A. Glass fibres, A. Polymer matrix composites (PMCs), B. Fracture, D. Non-destructive testing",
    author = "Jespersen, {Kristine M.} and Glud, {Jens A.} and Jens Zangenberg and Atsushi Hosoi and Hiroyuki Kawada and Mikkelsen, {Lars P.}",
    year = "2018",
    month = "6",
    day = "1",
    doi = "10.1016/j.compositesa.2018.03.002",
    language = "English",
    volume = "109",
    pages = "481--497",
    journal = "Composites - Part A: Applied Science and Manufacturing",
    issn = "1359-835X",
    publisher = "Elsevier Limited",

    }

    TY - JOUR

    T1 - Uncovering the fatigue damage initiation and progression in uni-directional non-crimp fabric reinforced polyester composite

    AU - Jespersen, Kristine M.

    AU - Glud, Jens A.

    AU - Zangenberg, Jens

    AU - Hosoi, Atsushi

    AU - Kawada, Hiroyuki

    AU - Mikkelsen, Lars P.

    PY - 2018/6/1

    Y1 - 2018/6/1

    N2 - The current work studies the fatigue damage initiation and progression in a quasi-unidirectional non-crimp fabric based fibre composite used for wind turbine blades. This is done by combining in situ transilluminated white light imagining (TWLI) with ex-situ X-ray computed tomography (CT) experiments along with tension clamp X-ray CT experiments. TWLI is used to monitor the off-axis cracks in the thin supporting backing fibre bundles present in quasi-UD composites, and a crack counting algorithm is applied to automatically count the cracks in images obtained in situ during fatigue testing. It is found that off-axis cracks not only initiate at the specimen edges but also at isolated locations inside the specimen, which could be related to the microstructural features. In addition, a clear effect of strain level on the measured off-axis crack density is observed. From the X-ray CT experiments, it is found that the UD fibre fractures initiate and progress from regions where the off-axis backing fibre bundles are ‘in contact’ with a UD fibre bundle. Damage is seen to first initiate at a cross-over region of the backing fibre bundles, and later at a region with only one backing fibre bundle. In addition, applying tension to the specimen during X-ray CT scanning is found to reveal additional UD fibre fractures that are not visible in scans performed the unloaded state. With load applied, a significant number of UD fibre fractures were observed earlier in the fatigue life than expected. Based on the observations of the study a damage progression scheme is presented for quasi-UD fibre composites.

    AB - The current work studies the fatigue damage initiation and progression in a quasi-unidirectional non-crimp fabric based fibre composite used for wind turbine blades. This is done by combining in situ transilluminated white light imagining (TWLI) with ex-situ X-ray computed tomography (CT) experiments along with tension clamp X-ray CT experiments. TWLI is used to monitor the off-axis cracks in the thin supporting backing fibre bundles present in quasi-UD composites, and a crack counting algorithm is applied to automatically count the cracks in images obtained in situ during fatigue testing. It is found that off-axis cracks not only initiate at the specimen edges but also at isolated locations inside the specimen, which could be related to the microstructural features. In addition, a clear effect of strain level on the measured off-axis crack density is observed. From the X-ray CT experiments, it is found that the UD fibre fractures initiate and progress from regions where the off-axis backing fibre bundles are ‘in contact’ with a UD fibre bundle. Damage is seen to first initiate at a cross-over region of the backing fibre bundles, and later at a region with only one backing fibre bundle. In addition, applying tension to the specimen during X-ray CT scanning is found to reveal additional UD fibre fractures that are not visible in scans performed the unloaded state. With load applied, a significant number of UD fibre fractures were observed earlier in the fatigue life than expected. Based on the observations of the study a damage progression scheme is presented for quasi-UD fibre composites.

    KW - A. Glass fibres

    KW - A. Polymer matrix composites (PMCs)

    KW - B. Fracture

    KW - D. Non-destructive testing

    UR - http://www.scopus.com/inward/record.url?scp=85054861474&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=85054861474&partnerID=8YFLogxK

    U2 - 10.1016/j.compositesa.2018.03.002

    DO - 10.1016/j.compositesa.2018.03.002

    M3 - Article

    AN - SCOPUS:85054861474

    VL - 109

    SP - 481

    EP - 497

    JO - Composites - Part A: Applied Science and Manufacturing

    JF - Composites - Part A: Applied Science and Manufacturing

    SN - 1359-835X

    ER -