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Discrete wavelet transform is the useful means for crack identification of beam structures. However, its accuracy is severely dependent on the selecting mother wavelet and vanishing moments, which raises a significant challenge in practical structural crack identification. In this paper, a novel approach is introduced for structural health monitoring of beams to fix this challenge. The approach is based on the combination of statistical characteristics of vibrational mode shapes of the beam structures and their discrete wavelet transforms. First, this paper suggests using regression statistics between intact and damaged modes to monitor the health of beam structures. Then, it suggests extracting quasi-Pearson-based mode shape index of the beam structures to use them as an original signal in discrete wavelet transforms. Findings show that the proposed approach has several advantages compared with the conventional mode shape signal processing by the discrete wavelet transforms and significantly improves damage detection’s accuracy.

The current study aims to investigate the facesheet dynamic pulse buckling of simply supported, cylindrical composite sandwich panels using the Budiansky–Roth buckling criterion. The foam core has been modeled with isotropic elastic-perfectly plastic properties and various failure modes of the sandwich panel like facesheet fracture, foam shear fracture, and foam yield are investigated. The extended high-order sandwich panel core theory was used to model the compressibility of the core. To study the mechanical properties of the viscoelastic foam core, the Kelvin–Voigt linear viscoelastic model was applied. The transient responses and stress components obtained from the present method are compared with finite element solutions using commercial software ANSYS and those reported in the literature. Accordingly, reasonable agreement is observed. It was shown that the pulse local buckling strength of the panel increases with a decrease in the panel radius or an increase in the thickness of the panel, and facesheet fracture is considered more a likely failure mode of these sandwich panels.

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