Analysis of residual transverse stresses in a thick UD glass/polyester pultruded profile using hole drilling with strain gage and digital image correlation

Onur Yuksel, Ismet Baran*, Nuri Ersoy, Remko Akkerman

*Corresponding author for this work

    Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

    1 Citation (Scopus)

    Abstract

    Process induced stresses inherently exist in fiber reinforced polymer composites particularly in thick parts due to the presence of non-uniform cure, shrinkage and thermal expansion/contraction during manufacturing. In order to increase the reliability and the performance of the composite materials, process models are developed to predict the residual stress formation. The accuracy of the process models is dependent on the geometrical (micro to macro), material and process parameters as well as the numerical implementation. Therefore, in order to have reliable process modelling framework, there is a need for validation and if necessary calibration of the developed models. This study focuses on measurement of the transverse residual stresses in a relatively thick pultruded profile (20×20 mm) made of glass/polyester. Process-induced residual stresses in the middle of the profile are examined with different techniques which have never been applied for transverse residual stresses in thick unidirectional composites. Hole drilling method with strain gage and digital image correlation are employed. Strain values measured from measurements are used in a finite element model (FEM) to simulate the hole drilling process and predict the residual stress level. The measured released strain is found to be approximately 180 μm/m from the strain gage. The tensile residual stress at the core of the profile is estimated approximately as 7-10 MPa. Proposed methods and measured values in this study will enable validation and calibration of the process models based on the residual stresses.

    Original languageEnglish
    Title of host publicationProceedings of the 21st International ESAFORM Conference on Material Forming, ESAFORM 2018
    PublisherAmerican Institute of Physics
    Volume1960
    ISBN (Electronic)9780735416635
    DOIs
    Publication statusPublished - 2 May 2018
    Event21st International ESAFORM Conference on Material Forming, ESAFORM 2018 - Palermo, Italy
    Duration: 23 Apr 201825 Apr 2018
    Conference number: 21
    http://www.esaform2018.com/index.php/en/

    Conference

    Conference21st International ESAFORM Conference on Material Forming, ESAFORM 2018
    Abbreviated titleESAFORM 2018
    CountryItaly
    CityPalermo
    Period23/04/1825/04/18
    Internet address

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  • Cite this

    Yuksel, O., Baran, I., Ersoy, N., & Akkerman, R. (2018). Analysis of residual transverse stresses in a thick UD glass/polyester pultruded profile using hole drilling with strain gage and digital image correlation. In Proceedings of the 21st International ESAFORM Conference on Material Forming, ESAFORM 2018 (Vol. 1960). [020040] American Institute of Physics. https://doi.org/10.1063/1.5034841