Coupling Analysis of Vibration and Fatigue for the Cracked Beam
Liu wenguang1,2; Chen guoping1
(1. College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics Nanjing 20016，China；2.School of Aeronautical Manufacturing Engineering, Nanchang Hangkong University Nanchang 330063，China)
Abstract：Abstract: An analytical method about vibration fatigue of cracked beam was proposed based on timing analysis and Paris equation. Coupling relationship between vibration and fatigue crack growth was considered by using timing analysis methods. Crack part was replaced by linear spring and damping loss factor was introduced by complex elastic modulus during vibration analysis. So that crack growth together with excitation frequency and damping were considered in the vibration analysis. Results indicate that crack length, excitation frequency and damping have important effects on the fatigue life of structural crack propagation. In the resonance region, the rate of crack growth is obvious and the speed is decreasing with damping increases. The structure far away from resonance region with crack propagation and the crack propagation speed increases with excitation frequency near to natural frequency. The prediction precision of fatigue life can be further improved through using this new analytical method.
2011, Vol. 30 
