Detection of on-aircraft fatigue cracks in a UH-60A planet carrier using spectral averaging

Abstract

In this paper, a new method for planet carrier fatigue crack detection is presented. This method begins by time synchronously resampling vibration signals to segment the signals according to shaft crossing times, such that an even number of data points are obtained to compute a spectral average. Then, the result is used to extract features and evaluate numerous condition indicators (CIs) for planet carrier fatigue crack detection. The methodology is validated using data from a number of US Army UH-60A Black Hawk helicopter main transmissions. The results are presented using vibration measurements of faulted and unfaulted transmissions over low-torque levels in on-aircraft conditions.

System for detecting the location of object fractures based on time-of-flight

“…To improve the strength and stiffness of the structure and provide experimental data for the further structural design, it is necessary to clarify the fracture position in experimental structures [8][9][10][11], forming the basis for traditional object fracture position detection. The most used detection methods include direct observation, image analysis, ultrasonic non-destructive detection, microwave non-destructive detection, and embedded optical fiber detection using optical time-domain reflectometry [12][13][14][15][16]. However, they are usually ground-based because of the high price and large volume of equipment needed.…”