Processing and interpretation of crack-propagation sensors

Abstract

The goal of gearbox prognostics, once a failure has been detected, is to estimate the degree of damage. Development of probabilistic damage assessment requires high quality ground truth. The present report describes practical analysis, processing, and interpretation of signals from crack-propagation sensors and damage estimation during gear teeth crack propagation. The study considers two types of crack propagations: one for a fatigue-tester-based crack propagation, and the other for a propagation in a gearbox. Crack closing occurs in both types of crack propagation and must be accounted for in assessing the damage. The analysis is conducted for sensors connected as a voltage divider. Signal conditioning and wire breakage inference are examined in detail. In addition, we discuss how equipping each gear tooth with two crack-propagation sensors, one on each gear face, can provide a better damage estimation.