Fatigue fracture of the Björk–Shiley heart valve strut and failure diagnosis from acoustic signatures

Repeated loading of the outer strut leg of the Björk–Shiley 60° convexo-concave (BSCC) valve results in fatigue crack propagation, with a duration from a few months to a few years. Sound and vibration analysis emitted from the strut of the BSCC valve due to impact is used to monitor the propagation of the fatigue crack before it would lead to the failure of one or both legs of the outlet strut. Analytical and experimental results established that the range of the fundamental natural frequency is 4000–8000 Hz. Analysis of sound emitted from the strut of the valve due to impact may be used to monitor the propagation of the fatigue crack before it would lead to the failure of the one or both legs of the outlet strut.