Formation of cryobiaxial-induced damage in tape-laminate composites. (1st March 2020)

• Record Type: Journal Article
• Authors: French, Jordan; Dahlkamp, Chris; Czabaj, Michael
• Is Part Of: Composite structures. Volume 235(2020)
• Publication Date: 2020-03-01
• Subjects: Matrix cracking -- Damage mechanics -- CT analysis -- Mechanical testing; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2019.111816
• Languages: English
• ISSNs: 0263-8223

Abstract

Abstract: The aim of this study is to investigate progressive formation of cryobiaxial-induced damage in tape-laminate composites intended for use in space-launch-vehicle cryotanks. A new test method is developed to evaluate three stacking sequences subjected to biaxial loading at room and liquid-nitrogen temperatures. Ex situ X-ray computed tomography is used intermittently between loading intervals to image formation and progression of ply-level damage. The mechanisms governing damage evolution are found to be the same for all stacking sequences, regardless of test temperature; however, at a given mechanical load, the low-temperature specimens exhibit significantly more cracking due to increased thermal-residual stresses. In all cases, ply damage is dominated by formation of stitch cracks, which only propagate through-thickness when the relative angle between adjacent plies is less than 45°. Based on findings in this study, a set of guidelines are proposed for the design of tape-laminates that are resistant to cryobiaxial-induced loading.