Volume 4, Issue 3 (May 1976)
Monitoring to Determine the Dynamics of Fatigue Testing
These investigations were begun to monitor the sonic response during the fatigue life testing of cantilever specimens; they led to the discovery that the power spectral density from the second overtone (3 × fundamental) changed with time, originally exceeding that from the fundamental. Overtones may have a pronounced influence on fatigue testing, and the experimental results should lead to consideration of the possible dynamic effects introduced by such overtones. Tests show that changes can be detected as a consequence of work hardening and crack growth. Possibly this method may be developed as a nondestructive testing technique.