Dynamometer Evaluation of Aircraft Wheel Microinspection Techniques

This paper reports the use of periodic microstructure observations as a possible supplement to existing inspection techniques for aircraft wheels and as an indicator of expended fatigue life. Inspection techniques were evaluated in the process of testing. Dye penetrant, eddy current, and replica (or microscopic) inspection techniques were performed at l0% increments of the estimated fatigue life. Results showed that microstructure did not change significantly during dynamometer testing and that of the three inspection methods, eddy current and replica techniques were more sensitive. The paper concludes that no practical assessment of expended fatigue life can be gained by monitoring microstructure.