PSI - Issue 68

R. Lach et al. / Procedia Structural Integrity 68 (2025) 1337–1342 R. Lach et al. / Structural Integrity Procedia 00 (2025) 000–000

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Lach, 2021). This can be triggered by optimum processing parameters and good fibre–matrix adhesion. The fibre– matrix adhesion quantifiable by the crack initiation toughness in fibre orientation also affects the crack initiation toughness cross to the fibre orientation, because fibre pull-out is the main energy-dissipative failure mechanism inside the UD tapes (see Fig. 5).

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Fig. 5. Comparison of the fracture toughness in and cross to fibre orientation PP/GF (a) and PA6/CF (b).

Furthermore, correlations between UD-tape morphology and toughness have been found. The roughness data measured in fibre orientation correlate well with the crack initiation toughness in fibre orientation and can be used to trigger novel morphology–property relationships (Fig. 6).

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Acknowledgements The investigations were funded by the Federal Ministry of Education and Research (BMBF) in line with the funding framework „FHprofUnt 2015“ (acronym: HerDeLaUD, grant number: 13FH056PX5) and by the Investitionsbank Sachsen-Anhalt (acronym: ModCF, grant numbers: 2004/00059 (PSM) and 2004/00060 (IMWS)). References Anderson, T. L., 2005. “Fracture Mechanics – Fundamentals and Applications” . 3rd ed., CRC Press, Boca Raton. Clutton, E., 2021. Essential Work of Fracture. In: Moore, D. R., Pavan, A., Williams, J. G. (Eds.). “ Fracture Mechanics Testing Methods for Polymers” . ESIS Publication 28, Elsevier, Amsterdam, 177–195. Lach, R., Schneider, K., Weidisch, R., Janke, A., Knoll, K., 2005. Application of the Essential Work of Fracture Concept to Nanostructured Polymer Materials. European Polymer Journal 41, 383–392. Lach, R., Teuscher, N., 2023. Modifizierte Carbonfasern – endlosfaserverstärkte UD-Tapes für optimierten Lasttransfer im Bauteil. Final Report (funder: IB Sachsen-Anhalt, acronym: ModCF, grant numbers: 2004/00059 and 2004/00060), PSM and IMWS , Merseburg and Halle/Saale. Tillner, B., Key, L. C., Lach, R., Langer, B., Michel, P., 2020. Untersuchung zur verfahrenstechnischen Herstellung, den Werkstoffeigenschaften und dem Delaminationsverhalten von unidirektional verstärkten Faser-Kunststoff-Verbunden (FKV) für den Strukturleichtbau. Final Report (funder: BMBF, acronym: HerDeLaUD, grant number: 13FH056PX5), Hochschule Merseburg, Merseburg. Tillner, B., Lach, R., 2021. Innovative Faser-Thermoplastverbunde – gezielte Materialentwicklung für höchste Ansprüche. Bau im Blick (BiB) No 2, 20–21.