Photoelasticity

Artificial double refraction is termed as photoelasticity. Here a solid is producing double refraction (and hence plane polarized light) when it is subjected to mechanical stress. This concept is widely used nowadays in structural engineering. Intricate problems are solved by employing this concept in structural engineering. This phenomenon was first observed in the year 1815 by David Brewster. Practical application of this phenomenon is in measuring stresses in machine parts. Stress analysis is a major step in machine design and manufacturing. Using this method, machine failures caused by inappropriate design, faulty stress distribution, etc. can be eliminated. Thus the knowledge of photoelasticity helps structural engineers to visualize an ample stress pattern which actually are beyond the reach of calculation.