Prediction of Onset of Mode I Delamination Growth under a Tensile Spectrum Load | Chapter 07 | New Advances in Materials Science and Engineering Vol. 2
In this investigation, the onset of mode I delamination growth under a standard aircraft spectrum load sequence, mini-FALSTAFF truncated to contain only tension-tension fatigue cycles is predicted. The study was carried out on a standard Double Cantilever Beam (DCB) test specimen of Uni Directional (UD) layup Carbon Fiber Composite (CFC) IMA/M21. Finite element modeling and analysis was carried out using ABAQUS standard to determine Strain Energy Release Rate (SERR) by Virtual Crack Closure Technique (VCCT). Both two dimensional (2D) and three dimensional (3D) models were studied. Using the FE analysis results, an empirical equation was derived for SERR (G) and load (P) relationship. Further, the load cycles in the spectrum sequence were rain flow counted to separate individual cycles. For each of the counted cycle, the SERR was obtained and corresponding N onset for that cycle was estimated from the Constant Onset Life Diagram (COLD) of the material. Linear damage accumulation law...