Abstract:To accurately measure the high-temperature dynamic strain of hot-section components of aero-engines, this paper systematically investigates a high-temperature dynamic strain measurement method based on fiber optic sensing technology. High-temperature-resistant grating structures, inscribed using femtosecond lasers, were installed and fabricated on the substrate surface via plasma spraying technology. The performance of the sensors was tested and evaluated using high-temperature static and dynamic strain calibration rigs that simulate the operating conditions of hot-section components. Finally, validation was conducted through two aero-engine test rig experiments. The results from disk rig tests designed to assess high-temperature endurance and measurement accuracy demonstrated that the sensors could withstand environments up to 650 ℃, with a deviation of less than 5% between measured centrifugal strain and design simulations. The results from high- and low-cycle fatigue rig tests designed to verify dynamic strain measurement capabilities under blade vibration loads indicated a discrepancy of approximately 1.3% between measured and theoretical resonance frequencies, while the dynamic strain amplitudes were consistent with the predicted design magnitudes. The high-temperature dynamic strain measurement method based on fiber optic sensing technology provides important technical support for accurately assessing stress distribution and fatigue life of hot-section components in aero-engines and identifying danger points in advance.