Strain measurement on blade and the calculation of blade stress during test are critical to determine the actual stress and the life of blades. Since the dynamic loads acting on blades, such as gas pressures and load changes during operation, might not be known, the concept of strain amplification factor (SAF) can be used to estimate the maximum strain/stress of blade during resonance. The SAF is defined as a ratio between the maximum modal strain on blade from FE analysis and the measured strain or computed strain of a particular place on blade. In this paper, this concept is reviewed and further analysis is carried out. To verify the theoretical analysis, the experimental tests of a radial turbine (blisk) are performed in detail. However, only experiments in static condition are considered in this work, since a better experimental condition can be achieved. Moreover, the verification of rotating blades could be accomplished with the similar procedure. The FE method is chosen as a tool to provide theoretical results. Two computations by using FE method are performed to obtain the SAFs. The first computation considers the use of sector model of turbine, which is usually practiced in industry. In the second calculation, the complete tuned turbine is taken into account. The obtained results for both computations and the effect of mistuning on SAF are discussed. Furthermore, the computed SAFs are compared to the experimental results.

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