Structural evaluation of roll quality and in-roll stress analysis using a novel on-line measurement technique

In a previous paper (Jaafar et al., 1999) we reported on the rudimentary development of a new technique for the on-line measurement of a roll's coefficient of restitution (Cr) as it is being wound, and enunciated the theoretical underpinnings behind the development. In this paper, the Cr sensor has been used to evaluate the radial and tangential roll behavior as it is being built. Based on the experimental findings, numerical simulations are proposed for modeling, using energy-based formulations, radial modulus and tangential stress as a function of roll radius. The simulations take into account the additive effect of winding operations, and corrects for the use of such idealized set-ups as the stack experiment, first proposed by Pfeiffer (1966), by incorporating increasing number of layers.In addition to basic structural assessment of roll quality in real time, a set of experiments have been devised to garner a fundamental understanding of the in-roll stress variations, based on which new insight into the constitutive relations is presented