Performance-Based Inspection Techniques for Turbine Engine Blades and Rotors

Bladed disk assemblies found in jet engines feature random and intentional variations in blade geometries. These variations result in a phenomenon called mistuning, and are caused by manufacturing tolerances, operational wear, and/or intentional changes in geometry. Mistuning can lead to forced response amplitudes that are much larger than would be observed by a tuned assembly (i.e. all blades are structurally and aerodynamically identical). Even small mistuning effects can lead to large asymmetric forced response. Contrastingly, intentional mistuning seeks to minimize the system's forced response amplitudes. Since structural mistuning can dominate the system's forced response amplitudes, it can control the high cycle fatigue life of bladed discs. Tools generated in phase I and II of this proposal will create and translate high-fidelity CAD models into structural finite element analysis (FEA) elements and computational fluid dynamics (CFD) grids. The analysis capabilities developed in phase I and II include the ability to perform modal analysis, forced response, mistuning, sensitivity analysis, and damage tolerance, steady and unsteady aero calculations, and Fluid Structure Interaction Analysis (FSI).