* '''Photoelastic models''' provide information on stress magnitude and orientation. They are made of transparent materials such as clear plastics or gelatins. When deformed and examined in polarized light, these materials exhibit color fringes and alternating light and dark bands. From these, we can determine the stress intensity and the orientation of the principal stresses at any point in the model. | * '''Photoelastic models''' provide information on stress magnitude and orientation. They are made of transparent materials such as clear plastics or gelatins. When deformed and examined in polarized light, these materials exhibit color fringes and alternating light and dark bands. From these, we can determine the stress intensity and the orientation of the principal stresses at any point in the model. |