Analysis of the elastic wave behavior in a cracked shaft

A new method currently under development for rotating shaft crack detection is presented. The underlying approach is to utilize the impact inherent in the once-per-revolution closing of a shaft crack. The axially traveling elastic compression wave, which is initiated by this impact, propagates to both ends of the shaft at the governing acoustic velocity. Provided suitable measurement near the shaft ends can detect the wave's arrival, then extracting both the crack location and size is thereby feasible. Proof-of-concept for this new method for shaft crack detection utilizes one-dimensional wave propagation simulations and a newly designed test apparatus, which are presented.