Through Thickness Residual Stress Measurements by Neutron Diffraction and Hole Drilling in a Single Laser-Peened Spot on a Thin Aluminium Plate

M. Burak Toparli, Michael E. Fitzpatrick

    Research output: Contribution to journalArticle

    2 Citations (Scopus)

    Abstract

    Residual stress measurements are very challenging in thin aluminium plates. Rollinginduced crystallographic texture can lead to an S-shape fit when using the sin2ψ method for surface X-ray diffraction. Peak broadening and missing peaks can also be observed for synchrotron X-ray diffraction with conventional θ/2θ scanning due to texture. In addition, when measuring near the plate surfaces, partially-filled gauge volumes in neutron and synchrotron X-ray diffraction experiments will lead to "pseudo-strains", an apparent shift between measured and actual positions for the diffraction peak. Obtaining a meaningful value of d0 for strain calculations is another issue for diffraction experiments in thin plates. The low thickness also offers challenges for destructive methods including incremental hole drilling: there is no defined ASTM standard for measuring nonuniform residual stress profile for thin plates. In this work, 2-mm-thick Al2024-T351 plate was investigated for residual stress fields due to laser peening. Neutron diffraction measurements were carried out at POLDI (Pulse Overlap time-of-flight DIffractometer) at the Paul Scherrer Institute, Switzerland and the results are compared with incremental hole drilling.

    Original languageEnglish
    Pages (from-to)167-172
    Number of pages6
    JournalMaterials Science Forum
    Volume772
    DOIs
    Publication statusPublished - 2014
    Event6th International Conference on Mechanical Stress Evaluation by Neutrons and Synchrotron Radiation - Hamburg, Germany
    Duration: 7 Sep 20119 Sep 2011

    Fingerprint

    stress measurement
    Stress measurement
    Neutron diffraction
    Aluminum
    drilling
    residual stress
    neutron diffraction
    Residual stresses
    Drilling
    aluminum
    Synchrotrons
    X ray diffraction
    Lasers
    Textures
    Diffraction
    diffraction
    thin plates
    lasers
    Shot peening
    Diffractometers

    Keywords

    • Incremental hole drilling
    • Laser peening
    • Neutron diffraction
    • Pseudo-strains
    • Residual stresses

    ASJC Scopus subject areas

    • Materials Science(all)
    • Condensed Matter Physics
    • Mechanical Engineering
    • Mechanics of Materials

    Cite this

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    title = "Through Thickness Residual Stress Measurements by Neutron Diffraction and Hole Drilling in a Single Laser-Peened Spot on a Thin Aluminium Plate",
    abstract = "Residual stress measurements are very challenging in thin aluminium plates. Rollinginduced crystallographic texture can lead to an S-shape fit when using the sin2ψ method for surface X-ray diffraction. Peak broadening and missing peaks can also be observed for synchrotron X-ray diffraction with conventional θ/2θ scanning due to texture. In addition, when measuring near the plate surfaces, partially-filled gauge volumes in neutron and synchrotron X-ray diffraction experiments will lead to {"}pseudo-strains{"}, an apparent shift between measured and actual positions for the diffraction peak. Obtaining a meaningful value of d0 for strain calculations is another issue for diffraction experiments in thin plates. The low thickness also offers challenges for destructive methods including incremental hole drilling: there is no defined ASTM standard for measuring nonuniform residual stress profile for thin plates. In this work, 2-mm-thick Al2024-T351 plate was investigated for residual stress fields due to laser peening. Neutron diffraction measurements were carried out at POLDI (Pulse Overlap time-of-flight DIffractometer) at the Paul Scherrer Institute, Switzerland and the results are compared with incremental hole drilling.",
    keywords = "Incremental hole drilling, Laser peening, Neutron diffraction, Pseudo-strains, Residual stresses",
    author = "{Burak Toparli}, M. and Fitzpatrick, {Michael E.}",
    year = "2014",
    doi = "10.4028/www.scientific.net/MSF.772.167",
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    journal = "Materials Science Forum",
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    T1 - Through Thickness Residual Stress Measurements by Neutron Diffraction and Hole Drilling in a Single Laser-Peened Spot on a Thin Aluminium Plate

    AU - Burak Toparli, M.

    AU - Fitzpatrick, Michael E.

    PY - 2014

    Y1 - 2014

    N2 - Residual stress measurements are very challenging in thin aluminium plates. Rollinginduced crystallographic texture can lead to an S-shape fit when using the sin2ψ method for surface X-ray diffraction. Peak broadening and missing peaks can also be observed for synchrotron X-ray diffraction with conventional θ/2θ scanning due to texture. In addition, when measuring near the plate surfaces, partially-filled gauge volumes in neutron and synchrotron X-ray diffraction experiments will lead to "pseudo-strains", an apparent shift between measured and actual positions for the diffraction peak. Obtaining a meaningful value of d0 for strain calculations is another issue for diffraction experiments in thin plates. The low thickness also offers challenges for destructive methods including incremental hole drilling: there is no defined ASTM standard for measuring nonuniform residual stress profile for thin plates. In this work, 2-mm-thick Al2024-T351 plate was investigated for residual stress fields due to laser peening. Neutron diffraction measurements were carried out at POLDI (Pulse Overlap time-of-flight DIffractometer) at the Paul Scherrer Institute, Switzerland and the results are compared with incremental hole drilling.

    AB - Residual stress measurements are very challenging in thin aluminium plates. Rollinginduced crystallographic texture can lead to an S-shape fit when using the sin2ψ method for surface X-ray diffraction. Peak broadening and missing peaks can also be observed for synchrotron X-ray diffraction with conventional θ/2θ scanning due to texture. In addition, when measuring near the plate surfaces, partially-filled gauge volumes in neutron and synchrotron X-ray diffraction experiments will lead to "pseudo-strains", an apparent shift between measured and actual positions for the diffraction peak. Obtaining a meaningful value of d0 for strain calculations is another issue for diffraction experiments in thin plates. The low thickness also offers challenges for destructive methods including incremental hole drilling: there is no defined ASTM standard for measuring nonuniform residual stress profile for thin plates. In this work, 2-mm-thick Al2024-T351 plate was investigated for residual stress fields due to laser peening. Neutron diffraction measurements were carried out at POLDI (Pulse Overlap time-of-flight DIffractometer) at the Paul Scherrer Institute, Switzerland and the results are compared with incremental hole drilling.

    KW - Incremental hole drilling

    KW - Laser peening

    KW - Neutron diffraction

    KW - Pseudo-strains

    KW - Residual stresses

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