Prediction of mode II delamination propagation life under a standard spectrum loading in a carbon fiber composite. (August 2017)

• Record Type: Journal Article
• Authors: Anilchandra, AR; Bojja, Ramesh; Jagannathan, N; Manjunatha, CM
• Is Part Of: Journal of composite materials. Volume 51:Number 20(2017)
• Page Start: 2827
• Page End: 2833
• Publication Date: 2017-08
• Subjects: Fatigue -- composite -- spectrum load -- FALSTAFF -- delamination; Composite materials -- Periodicals; Composites -- Périodiques; 620.118
• DOI: 10.1177/0021998316684656
• Languages: English
• ISSNs: 0021-9983

Abstract

Mode II constant amplitude fatigue delamination propagation tests were conducted at three different stress ratios, viz. R = 0.0, 0.5, and −1.0 using modified three-point bend test fixture and end notched flexure (ENF) test specimens of unidirectional IMA/M21 carbon fiber composite. Delamination length was measured by compliance technique. The delamination propagation rate (da/dN) plots were constructed for various stress ratios. Using an equivalent energy release rate concept, Geq, all the curves were merged into a single curve in the form of Paris equation, da/dN = C(Geq ) k . The Paris constants, C and k, determined from the experimental results were subsequently used in predicting the delamination propagation life under a standard mini FALSTAFF spectrum load sequence. Experiments were also conducted under the same spectrum load sequence with various reference loads to determine the propagation lives. A reasonably good correlation was observed between the predicted and experimental mode II delamination propagation life under spectrum loads.