Automatic fracture photoelastic analysis of a tempered thick glass plate

The photoelastic method was used to measure the residual stresses existing in selected areas of a cabin door that are considered critical in the failure of the same door. The technique was applied to samples taken from a door that was broken to obtain samples. Of the total measured samples, the average residual stresses was measure. For comparison purpose, the obtained values of residual stresses were compared with the values related to flat glass windows in transportation vehicles. The residual stresses are important in determining the modulus of rupture of the glass. The higher the residual stresses are, the higher the modulus of rupture of the glass is.