Procedure for residual stress profile determination by curvature measurements

A procedure is presented for the measurement of residual stress profile in regular geometry bodies such as plates and disks. The experimental work is based on the sole measurement of the sample curvature deriving from progressively etching one of its surfaces. A relationship is obtained to correlate curvature data as function of etching depth to the original residual stress profile. The sensitivity of the method and the influence of possible experimental errors are analyzed. The technique is then applied to strengthened glass samples produced by both thermal tempering and ion exchange and obtained results are compared to data obtained by available alternative technique to demonstrate the validity of the proposed approach.