Effect of Resonant Frequency Shifting on Time to Failure of a Cantilevered Beam under Vibration

Many vibration screening programs have implemented the use of repetitive shock (RS) machines. Examination of the RS power spectral density (PSD) shows there are many high and low points throughout the frequency band. The effect of these sharp peaks and valleys on the time to failure of a test item was unknown. A simple cantilevered beam was subjected to several vibration profiles with peaks and valleys. It was determined that the peaks and valleys had a significant effect on the time to failure due to resonant shifting of the beam during crack propagation.