Asymmetric tensioning of circular saws

Abstract

The most frequently used tensioning methods are hammering and roll tensioning. The effectiveness of hammering depends heavily on the skill of the saw filer. Roll tensioning is a well understood technique that yields increases in some natural frequencies while decreasing others. Thus, an optimal tensioning exists beyond which further rolling buckles the saw into a “dish” shape. This paper introduces a new tensioning method in which the natural frequencies associated with all the saw vibration modes are increased simultaneously. An eccentric hole is introduced into the saw, and a uniform normal pressure is applied to the face of the hole. The natural frequencies increase monotonically with increased pressure, and the magnitude of the shifts increase with the introduction of additional stressed holes. Hole eccentricity affects which natural frequencies are altered most, so the tensioning can be directed towards optimal increases in certain vibration modes. The predicted increases in the natural frequencies associated with the potentially unstable modes are limited only by the restrictions of classical plate theory and loading within unstable modes are limited only by the restrictions of classical plate theory and loading within the elastic limit of the saw.