Identification of tension distribution of thin plate using vibration characteristics (Accuracy improvement by batch identification of tension and stiffness distributions)

Abstract

The flatness of the metal thin plate shape is required in the production lines. Though, the convenient method for measuring small buckles of the thin plate has not been established. The tension distribution corresponding to the strain distribution is occurred by adding the strip running tension to the buckled thin plate. We propose an identification method by using natural frequencies and vibration modes, which are related to tension distributions of thin plate. In this paper, a new tension identification method in a thin plate using modal analysis method is investigated. We develop a simplified dynamic model of thin plate, and tension distribution is modeled by springs. A simplified model spring constants and bending stiffness are obtained by the least-squares method, which minimize the difference between a simplified model modal parameters and the given values. The authors apply the proposed identification method to a thin steel plate based on FEM analysis results. As a result, it is shown that identified tension distributions well corresponded to the FEM results.