Modal Filter for a Disk and Its Application to the Evaluation of Tensioning Effect on a Circular Saw(<Special Issue>Dynamics & Design Conference 2009)

Abstract

In order to properly evaluate the effect of tensioning on a circular saw, it is essential to use the change in natural frequency of the sawblade tensioned by rolling. This paper deals with a spatial filtering technique called the modal filter to easily measure the natural frequencies for the modes necessary for the evaluation of tensioning effect. The modes necessary for the evaluation are indicated based on the backward travelling wave frequencies of a rotating disk. The modal filter using point sensors, is designed based on the mode shapes of a disk. The examples show that the natural frequencies for the modes with the nodal diameters 0, 1 and 2 are necessary for the evaluation of tensioning effect. The information on the nodal diameters for the disk allows to easily determine the proper sensor positions for the modal filter for a disk such as a circular saw. The modal filter designed extracts the three modes separately from the experimental data obtained in the impact test of the disk.