Three-Dimensional Nonlinear Structural Analysis Methods for Gas Turbine Engine Metallic Components and Component Assemblies

The proposed system will be capable of providing diagnostic and prognostic nonlinear structural analysis for gas turbine engine metallic components and component assemblies. This approach will use vibration testing and analysis techniques that have proven to be successful for determining turbomachinery structural health, and tie them together with a software program utilizing “artificial intelligence”. Vibration data will be recorded with sensors in key locations during engine operation. This data will be analyzed by an autonomous software program using curve fitting of natural frequency peaks, interference diagrams, a detailed finite element model, and comparisons to previously recorded vibration signatures. When a shift in a natural frequency is detected by the on-board sensors, a simulated crack is introduced into the FEA model and its size and location are adjusted until the analytical vibration predictions match the measured data. The efficiency of this process is increased significantly by the use and understanding of an interference diagram, as the location and size of a crack can be deduced by knowing the specific modes that have been influenced. The results of the finite element model will provide the crack size and location information needed for detailed fracture mechanics calculations and predictions for remaining component life.