Correlation of Non-contact Full-Field Dynamic Strain Measurements with Finite Element Predictions

It is highly desirable to have the capability to measure strain maps on components directly and in a full-field fashion that addresses shortcomings of conventional approaches. In this paper, use of a 3D laser measurement system is explored for direct and full-field dynamic strain measurements on compressor and turbine rotor blades. More importantly, the results obtained are numerically correlated to corresponding FE predictions in a systematic manner. The ability to measure strain maps on real engine hardware is demonstrated not only for low frequency fundamental modes, but also for challenging high frequency modes. Correlation results show a high degree of agreement between measured and predicted strains, demonstrating the maturity of the technology and the validity of the method of integration used here. The measurements are repeated for a number of different loading amplitudes to assess the variations in strain fields. Although the application of 3D laser systems to measurements of full-field strain were explored in previous studies, to the best knowledge of authors, full-field numerical correlation of full-field strain on a wide range of real, complex components to this extent is presented here for the first time.