45. Vibration Fatigue Analysis of a Cantilever Beam Using Different Fatigue Theories

In this study, vibration fatigue analysis of a cantilever beam is performed using an in-house numerical code. Finite element model (FEM) of the cantilever beam verified by tests is used for the analysis. Several vibration fatigue theories are used to obtain fatigue life of the cantilever beam for white noise random input and the results obtained are compared with each other. Fatigue life calculations are repeated for different damping ratios and the effect of damping ratio is studied. Moreover, using strain data obtained from cantilever beam experiments, fatigue life of the beam is determined by utilizing time domain (Rainflow counting method) and frequency domain methods, which are compared with each other. In addition to this, fatigue tests are performed on cantilever beam specimens and fatigue life results obtained experimentally are compared with that of in-house numerical code. It is observed that the accuracy of the damping ratio is very important for accurate determination of fatigue life. Furthermore, for the case considered, it is observed that the fatigue life result obtained from Dirlik method is considerably similar to that of Rainflow counting method.