Savitzky-Golay Smoothing and Differentiation Filters for Damage Identification in Plates

Abstract

The aim of this paper is to present a baseline-free method for the identification of slot edges in a square plate. The slots, created by reducing the plate thickness, have different geometries and are placed in several locations. We make use of Savitzky-Golay smoothing and differentiation filters for the computation of modal strains. These modal strains are computed by differentiating the modal displacements (mode shapes), which are obtained by the finite element method. A discussion on the set of Savitzky-Golay filter parameters to obtain the best damage identifications is presented. The influence of noise on the quality of these damage identifications is also studied. The norm of modal strains is found to be very sensitive to the stiffness decrease, allowing the identification of single damage (one slot) and multiple damage (three slots).