Cyclic fatigue delamination of carbon fiber-reinforced polymer-matrix composites: Data analysis and design considerations. (February 2016)

• Record Type: Journal Article
• Authors: Brunner, A.J.; Stelzer, S.; Pinter, G.; Terrasi, G.P.
• Is Part Of: International journal of fatigue. Volume 83:Part 2(2016)
• Page Start: 293
• Page End: 299
• Publication Date: 2016-02
• Subjects: Carbon fiber reinforced polymer-matrix composites -- Cyclic delamination fatigue -- Test development -- Data analysis -- Composite structural design; Materials -- Fatigue -- Periodicals; Materials -- Fatigue; Periodicals; 620.1122
• DOI: 10.1016/j.ijfatigue.2015.10.025
• Languages: English
• ISSNs: 0142-1123

Abstract

Highlights: Reviewing state-of-the-art of fatigue delamination test development. Discussing problems of fatigue delamination test under load control. Unidirectional CFRP laminates tend to yield low threshold values in fatigue. Fatigue delamination of CFRP is compared for different loading modes. Abstract: Activities toward standardization of fracture mechanics tests on carbon fiber-reinforced polymer-matrix (CFRP) composites have recently focused on cyclic fatigue under mode I (tensile opening), mode II (in-plane shear) and mixed-mode I/II loading. Data from recent round robins performed by Technical Committee 4 (TC4) of the European Structural Integrity Society (ESIS) and from preliminary testing of additional CFRP epoxy laminates at the authors' laboratories are analyzed with different approaches in attempts to reduce scatter and to identify parameters for CFRP structural design. Selected test data comparing load and displacement control for the cyclic fatigue tests are also discussed. Specifically, threshold values from Paris-law data fitting are compared with values from fitting with a modified Hartman–Schijve approach. Independent of the approach used for the analysis, mode I threshold values of selected CFRP seem to be in the range between about 30 and 100 J/m 2, i.e., roughly around the range of critical mode I energy release rate values (denoted by G IC ) obtained from fracture testing of neat commercial epoxy resins, but clearly below quasi-static initiation G IC -values for unidirectional CFRP composites. Implications for CFRP structural design based on mode I fatigue fracture mechanics test data are briefly discussed.