Experimental and numerical studies to estimate fatigue crack growth behavior of Ni-based super alloy

In this work, the fatigue crack growth behavior of the Nickel based super alloy is investigated at room (26 °C) and elevated temperature (650 °C). The fatigue crack growth experiments are performed to understand the effect of temperature and loading rate. The elasto plastic fracture toughness tests are performed to evaluate JIC. Paris law is used in conjunction with extended finite element method (XFEM) to numerically predict the fatigue life. The stress intensity factors of individual mode (KI and KII) are computed from J-integral by decomposing the stress, strain and strain derivatives into symmetric and antisymmetric parts. Few parametric studies are performed to show the mesh convergence and path independency of J-integral. Fatigue crack growth in an aero-engine turbine disc is predicted. The numerically predicted fatigue life is found in good match with the experimental results.