Conventionally strain measurements are done in an intrusive way, and, at one or a few discrete points. 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. The results are correlated to corresponding FE predictions in a systematic and quantified 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. The actual component geometries are scanned and component-specific FE models are created. By correlating the measurement results to those predicted from the reverse engineered FE models, it is demonstrated that the results are improved when actual geometries are taken into account. Although the application of 3D laser systems to measurements of full-field strain were explored in previous studies, to the best knowledge of the authors, full-field numerical correlation of full-field strain on a wide range of real, sophisticated components to this extent is presented here for the first time.

中文翻译：

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全场动态应变测量与逆向工程有限元模型预测的相关性

传统上，应变测量是以侵入方式进行的，并且是在一个或几个离散点上进行的。在本文中，探讨了使用 3D 激光测量系统对压气机和涡轮转子叶片进行直接和全场动态应变测量。结果以系统和量化的方式与相应的有限元预测相关。在真实发动机硬件上测量应变图的能力不仅在低频基模中得到了证明，而且在具有挑战性的高频模中也得到了证明。相关结果显示测量和预测应变之间的高度一致，证明了技术的成熟度和此处使用的集成方法的有效性。对许多不同的加载幅度重复测量以评估应变场的变化。扫描实际组件几何形状并创建组件特定的有限元模型。通过将测量结果与从逆向工程有限元模型预测的结果相关联，证明在考虑实际几何形状时结果得到改善。尽管在之前的研究中探索了 3D 激光系统在全场应变测量中的应用，但据作者所知，全场应变在各种真实、复杂组件上的全场数值相关性到这种程度这是第一次在这里介绍。