Observing progressive damage in carbon fiber epoxy laminate composites via 3D in-situ X-ray tomography

• Published in: Engineering fracture mechanics 2021-04, Vol.246, p.107626, Article 107626
• Main Authors: Ortiz-Morales, Alejandra M., Hanhan, Imad, Solano, Jose Javier, Sangid, Michael D.
• Format: Article
• Language: English
• Subjects: (A) Polymer-matrix composites; (B) Micromechanics; (C) Crack growth; (D) Aerospace vehicles; Breakage; Carbon fiber reinforced plastics; Crack initiation; Cracking (fracturing); Damage tolerance; Fiber composites; Fiber reinforced polymers; Image processing; Particulate composites; Polymer matrix composites; Synchrotron radiation; Synchrotrons; Three dimensional composites; Tomography
• ISSN: 0013-7944; 1873-7315
• DOI: 10.1016/j.engfracmech.2021.107626

As the use of fiber-reinforced polymer composites grows in aerospace structures, there is an emerging need to implement damage tolerant approaches. The use of in-situ synchrotron X-ray tomography enables direct observations of progressive damage relative to the microstructural features, which are studied in a T650/5320 laminate composite with two layups via monotonic tension. Specifically, the interactions of micromechanical damage mechanisms at the notch tip were analyzed through 3D image processing as the crack grew. The analysis showed intralaminar cracking was dominant during crack initiation, delamination became prevalent during the later stages of crack progression, and fiber breakage was, in general, largely related to intralaminar cracking. [Display omitted] •In-situ X-ray tomography was conducted on laminate composites with 45°plies.•Compact tension specimens allowed for a fracture mechanics 3D crack growth study.•3D image processing yielded visualizations of the interaction of damage mechanisms.•Intralaminar cracking was dominant and led to 66% of fiber breakage events.•Fiber bridging was directly observed at a +45°/-45°delamination event.