Anomalous Stress Profiles in Ion‐Exchanged Glass

Photoelastic measurements on specimens sliced from ion‐exchanged slabs and cylinders have revealed a tension maximum in the distribution of the axial stress. This maximum is not predicted by the conventional stress analysis, which assumes a plane stress condition and ignores the existence of an additional characteristic distance, the thickness of the exchanged layer. A 2‐dimensional finite element analysis under a generalized plane strain condition showed that a tension maximum in the axial stress occurs if the thickness of the slice from the plate is neither smaller than the layer thickness nor much greater than the plate thickness.