Impact damage detection in glass fibre reinforced polymers via electrical capacitance measurements on integrated carbon fibre bundles

• Published in: Composites communications 2022-02, Vol.30, p.101090, Article 101090
• Main Authors: Buggisch, Christina, Gibhardt, Dennis, Kern, Mareile, Fiedler, Bodo
• Format: Article
• Language: English
• Subjects: Delamination; Glass fibre; Multifunctional composite; Structural health monitoring
• ISSN: 2452-2139; 2452-2139
• DOI: 10.1016/j.coco.2022.101090

Impact damages are critical for fibre reinforced polymers, as they can lead to large delaminations that strongly influence the structural integrity of the components. Therefore, reliable detection of impact damages through structural health monitoring is desired. This paper demonstrates a method for the detection and size estimation of impact damages in glass fibre reinforced polymers using capacitance measurements on integrated carbon fibre bundles. Therefore, individual rovings of glass fibre fabrics are replaced by carbon fibre rovings. After infusion of the laminate, the electrical capacitance is measured between the carbon fibre bundles. Damage in the form of matrix cracks or delaminations results in incorporated air that changes the permittivity of the material and, therefore, can be detected as a capacitance decrease. Considering the magnitude of capacitance decrease, a size estimation of the impacts is possible. Consequently, the presented method can be used for in-situ monitoring of damages in glass fibre reinforced polymers. •Integrated carbon fibre bundles serve as capacitor electrodes in GFRP.•Structural health monitoring measuring the capacitance change.•Permittivity change due to damage results in a capacitance decrease.•Level of capacitance decrease allows estimation of impact damages’ size. [Display omitted]