High-Cycle Fatigue Testing of Turbine Blades Under Multiaxial Loading

摘要

Gas turbine engine blades are subjected to a centrifugal force in the radial direction and high frequency transverse excitation under operating conditions. A multiaxial loading machine was proposed in the present SBIR program to perform high-cycle fatigue testing on gas turbine engine blades. A GE F110 second stage fan blade was selected as the specimen for initial testing and design studies. The blade was modeled and analyzed using finite element analysis to determine the loading parameters required to simulate the operating conditions. These parameters were used as guidelines in designing the machine. The test frame, hydraulic components, control system, and data acquisition system have been integrated successfully into a fully functional multiaxial loading machine. The multi axial loading machine has three individual hydraulic actuators. One actuator is mounted in the vertical axis and is used to simulate the radial load on the blade. The other two actuators are mounted in the horizontal axis and are used to apply a transverse bending or torsion load to the blade at high frequencies. The multiaxial high frequency testing capability of the machine was demonstrated by running tests on trial specimen and an actual GE F110 second stage fan blade.