Performance analysis of octal rings as mechanical force transducers

The present work analyzes the characteristics of octal rings as mechanical force transducers. It uses a finite element model of the ring to determine its state of strain upon the application of load. It also correlates ring design parameters and performance measures, using an L9 orthogonal array of finite element simulations. Design parameters include height, thickness, width, and edge curvature. Performance measures include sensitivity and stiffness. Model simulation results showed a considerable variation in strain along ring face with a considerable difference in the maximum values of the tensile and compressive strains. They, also, revealed a region of a large tensile strain within the ring not addressed in the literature. Moreover, simulation results showed that increasing ring height and decreasing its thickness increases its sensitivity and decreases its stiffness. The width of the ring does not have clear effect of stiffness. However, increasing width decreases sensitivity. Ring edge radius has no significant effect on sensitivity while increasing the edge radius decreases stiffness. A developed relation between strain gauge length and average strain revealed an optimal gauge length that improves ring performance.