Photo‐Elasticity and Design Problems

PHOTO‐ELASTICITY is not a new subject. In recent years much progress has been made towards a simplified technique, so that this method of stress analysis is now becoming popular in industry, and is giving valuable information about the failure of engineering parts. There is no mystery about the method; the application of photo‐elasticity is found to require not so much the learned scientist for its satisfactory execution, but rather the man with a sound common sense and a knowledge of the fundamental principles underlying engineering problems. It is found, too, that if the method is intelligently applied it is comparatively cheap and can well repay itself by saving thousands of pounds worth of damage caused by failures under service conditions. To the practical designer photo‐elasticity provides him with one of the most powerful weapons by which he may analyse the stresses existing in complicated engineering parts. In effect the responsibility of a design is passed from the intuitive thought within a designer's mind to the certainty of facts.