Research on thermal-mechanical-vibration fatigue test technology of aero-engine compressor blade

Introduction Compressor blades in aero-engines are subjected to complex thermo-mechanical-vibration interactions under service conditions, with foreign object damage (FOD) further exacerbating fatigue failure risks. To accurately evaluate the high-cycle fatigue performance of blades under combined thermo-mechanical fatigue (TMF) and FOD in operational scenarios, this study developed a multi-physical coupled test system to simulate realistic service environments for rotating components. Methods A multi-physical coupled test platform was constructed to synchronously simulate thermo-mechanical-vibration interactions. The system achieves centrifugal load and temperature control with an error margin within 1%, while providing high-frequency vibration loading at 1,600 Hz with large displacement, accurately replicating the dynamic stress states of blades during operation. Experiments were conducted on GH4169G compressor blades with prefabricated FOD, systematically investigating synergistic fatigue effects under combined thermal, centrifugal, and vibrational loads. Results Experimental results indicate that under combined thermo-mechanical-vibration fatigue loading, low-cycle centrifugal load exerts the most significant influence on fatigue performance, followed by thermal load, with high-cycle vibration load having a relatively lesser effect. Foreign object damage markedly reduces fatigue strength, while an increase in the low-cycle load ratio moderately enhances both fatigue limit and fatigue life. The data further reveal interactive mechanisms of crack initiation and propagation under coupled loading conditions. Discussion He proposed multi-physical coupled testing methodology provides direct technical support for experimental evaluation, strength assessment, damage-tolerant design, and condition-based maintenance of aero-engine compressor blades. The findings emphasize the critical need to consider the coupling effects of low-cycle mechanical loads and FOD in fatigue design, offering experimental foundations for future fatigue resistance optimization and life prediction models. This approach can also be extended to multi-axial fatigue reliability studies of other rotating components.