Finite element analysis of machining processes of turbine disk of Inconel 718 high-temperature wrought alloy based on the theorem of minimum potential energy

Abstract

Machining processes of Inconel 718 turbine disk including turning and broaching processes are, respectively, analyzed using the theorem of minimum potential energy. First, in order to provide the initial condition in terms of elastic strain energy for the machining processes, two-dimensional, axial symmetry assumptions are adopted and the simulation of multi-stage forging of disk is conducted and verified by the residual stresses test. Secondly, potential energy (PE) expression for the machining processes is developed. The predicted results of turning and broaching indicate that there exists an optimal value of removed material, and high level of strain energy signifies an unstable state of the structure, which could make the part deform to keep self-equilibrium.