Effect of internal stress on the flexural stiffness of discs

Abstract Steel Discs of 12 in. outside diameter were centrally clamped while various combinations of transverse loads were applied at the outer edge. Measured stiffnesses obtained from an initially stress-free disc were found to agree with theoretical values. Further discs were subjected to hammering treatments to introduce internal stresses. After stiffness measurements were made, strain gauges were attached for measuring the internal stresses. A strain energy method was used for calculating the effect of these stresses on stiffness. Fair agreement was found between experimental and calculated values.