Modal Analysis of Diagonally Hat Stiffened Square Plate to Distinguish Spot Weld Rupture

Abstract

In the field of vibration engineering, Modal analysis is popularly used for structural analysis to determine its modal parameters like modal frequencies, mode shapes, and damping ratio. Hat stiffened structures are inherently used in all three kinds of transportation industries like automobiles, aviation, and marine. The change in the modal parameter values indicates the disintegration happened within the structure. In this paper, a square plate is stiffened with a hat channel along its one of the diagonal by applying spot welds on both flanges. A finite element model of this structure is solved using ANSYS software to obtain modal parameters. The results obtained from the finite element analysis are validated using the Experimental Modal analysis technique. Extreme welds on one side of the stiffener are separated from the plate, and new modal parameters are obtained using FE analysis and verified by EMA. The modal parameters assessment of both cases has shown a relation of weld partition with the intrinsic properties of the structure.