Calculating coilset based on curvature of a web

Abstract

A web which has passed over a roll can exhibit coilset due to differential yielding of fibers through its thickness. Modeling can provide a radius of curvature, R, the web would achieve if no external forces were applied. However, measuring this radius of curvature is often impractical and can be difficult when the radius of curvature becomes large. For tinplated steel products, a simple method of quantifying coilset is to hang a standard length of web on a wall, and measure the distance, C, the web curls off the wall. In this paper, the non-linear differential equations to determine the coilset measurement, C, from a given radius of curvature, R, are developed and solved numerically.