Optimum strain gage application to bladed assemblies

Optimum placements of the strain gages assure reliable vibration measurements of structural components such as rotating blades. Within the framework of cyclic vibration theory, a novel approach has been developed for computation of the optimum gage positions on tuned bladed disks regarding the determined sensitivity, orthogonality gradient and distance criteria. The utilized genetic algorithm optimization tool allows for an effective numerical search of suitable solutions of the defined optimization function. A rotating, impeller disk represented by a cyclic finite element model demonstrates the application of, this method. The present technique can be easily applied to other structural components requiring optimal strain gage instrumentation.