An Analytical Method for Vibration Fatigue of Cracked Beams

A new analytical method for vibration fatigue life of cracked beams was proposed with the structural response changes as crack growth. In analysis, the damping loss factor was introduced by the complex elastic modulus, and the crack growth was simulated by employing a Paris equation, and the coupling effect of vibration and crack growth was considered through vibration analysis and estimation of fatigue crack propagation cycles by cycles. Results indicate that impacts of exciting frequency and damping on the crack growth are obvious. The resonance fatigue crack growth rate decreases rapidly when big damping is involved, and the first mode is more important to the crack growth than that of other mode.