This paper presents the application of a novel vibration-based technique for detecting fatiguecracks in structures. The method utilizes the empirical mode decomposition method (EMD) toestablish an effective energy-based damage index. To investigate the feasibility of the method,fatigue cracks of different sizes were introduced in an aluminum beam subjected to a cyclic loadunder a three-point bending configuration. The vibration signals corresponding to the healthyand the damaged states of the beam were acquired via piezoceramic sensors. The signals werethen processed by the proposed methodology to obtain the damage indices. In addition, for thesake of comparison, the frequency and damping analysis were performed on the test specimen.The results of this study concluded with two major observations. Firstly, the method was highlysuccessful in not only predicting the presence of the fatigue crack, but also in quantifying itsprogression. Secondly, the proposed energy-based damage index was proved to be superior tothe frequency-based methods in terms of sensitivity to the damage detection and quantification.As a result, this technique could be regarded as an efficient non-destructive tool, since it issimple, cost-effective and does not rely on analytical modeling of structures. In addition, thecapability of the finite element method (FEM) in mimicking the experiments, and hence forconsideration as an effective tool for conducting future parametric studies, was alsoinvestigated
This paper presents the application of a novel vibration-based technique for detecting fatiguecracks in structures. The method utilizes the empirical mode decomposition method (EMD) toestablish an effective energy-based damage index. To investigate the feasibility of the method,fatigue cracks of different sizes were introduced in an aluminum beam subjected to a cyclic loadunder a three-point bending configuration. The vibration signals corresponding to the healthyand the damaged states of the beam were acquired via piezoceramic sensors. The signals werethen processed by the proposed methodology to obtain the damage indices. In addition, for thesake of comparison, the frequency and damping analysis were performed on the test specimen.The results of this study concluded with two major observations. Firstly, the method was highlysuccessful in not only predicting the presence of the fatigue crack, but also in quantifying itsprogression. Secondly, the proposed energy-based damage index was proved to be superior tothe frequency-based methods in terms of sensitivity to the damage detection and quantification.As a result, this technique could be regarded as an efficient non-destructive tool, since it issimple, cost-effective and does not rely on analytical modeling of structures. In addition, thecapability of the finite element method (FEM) in mimicking the experiments, and hence forconsideration as an effective tool for conducting future parametric studies, was alsoinvestigated