Structural health monitoring of cantilever castellated beams under natural frequency excitation

This paper presents a novel detail of the finite element simulation of the castellated cantilever beams using natural frequency vibration that is considered in the damage detection procedure. All models are analysed to compare the numerical results for free vibrations with their single-degree-of-freedom characteristics. The objective of this investigation is to explore a new method for detecting local damage in the structural health monitoring of castellated cantilever beams. Moreover, the study of structural health monitoring focuses on the use of a novel safe method for detecting damage to improve safety properties. The detection threshold is set at 12.7% of the relative curvature index that is used to detect the failure mode of local stiffness reduction. The natural frequencies and mode shapes are changed to lead to a crack, which causes a local stiffness reduction. Therefore, a failure mode is achieved by the inability of castellated cantilever beams to perform at the fifth mode shape. The results indicate that the failure mode occurred in the fifth mode shape of cantilever castellated beams, with a reduction of 14% compared to the healthy model. In addition, the normalised diagonals of the relative deformations in the modal assurance criterion indicate that healthy models perform well.