Fundamental mode shape-based damage detection in arbitrary shaped plates using a hybrid of contourlet transform and Delaunay triangulation

Abstract

The past studies have been focused on the field of the damage detection of rectangular plate structures. A major limitation of these studies is that the proposed methods can’t be used for arbitrary shaped plate structures. The main aim of this study is to present a new methodology based on a hybrid of the contourlet transform and the Delaunay triangular for the damage detection in arbitrary shaped plate structures. In the proposed method, the fundamental mode shape of arbitrary shaped plate is first simulated as a 2-D spatially-distributed signal. To achieve this purpose, the intact and damaged plates are separately inserted into a virtual rectangular, and the responses of the fundamental mode shape for the virtual rectangular plates are exploited by the Delaunay triangular as a most popular interpolation method. Then, the contourlet transform is applied to the mode shapes of intact and damaged plates. Finally, the location of damages is identified by a damage index which is obtained using the coefficients of the contourlet transform. The efficiency of the proposed method are investigated for several plate structures with different shapes and an experimental study. Numerical and experimental results show that the proposed method is capable of identifying the location of damages in rectangular and arbitrary shaped plate structures. It also appears that this method can reveal the location of one or multi-damages, and the main shape of actual plates.