The Numerical Simulation Of Fatigue Crack Propagation In Inconel 718 Alloy At Different Temperatures

Inconel 718 alloy is the most commonly used material of aero-engine turbine today.However,Inconel 718 alloy is known to suffer from the fatigue crack propagation during engine operation,which will lead to unstable fracture and seriously threatens the safety of the engine.In this paper,we research the fatigue crack propagation process of Inconel 718 alloy unilateral notched standard CT specimen at room temperature(298.15K),573.15 K and823.15 K under the type I cyclic fatigue load.The ABAQUS is used for numerical simulation.First,parametric models are established.Second,the extended finite element method(XFEM)is used in the calculation process for describing the crack state.Third,the stress intensity factor at the crack tip under different temperatures is calculated,and the extended finite element crack length is solved to obtain the fatigue crack growth rate da/d N curve.The results show that the simulated fatigue crack growth rate da/d N curve is basically consistent with the test results under the same conditions.Therefore,the numerical simulation method reported in this paper can provide a reference for fatigue tests at low stress intensity factors.