Photoelasticity

What is photo-elasticity?

Photo-elasticity is an experimental technique used to study and visualize stress distribution in transparent materials. When certain materials, like glass or plastic, are subjected to mechanical stress, their optical properties change. This phenomenon is called birefringence, where the material's refractive index varies with the applied stress.

Photoelasticity involves introducing polarized light into a stressed transparent material. As the light passes through the material, its polarization is altered due to the birefringence induced by the stress. This results in the formation of colorful patterns, known as fringes or isochromatics, which correspond to areas of different stress levels within the material.

Why do people carry out photo-elasticity testing?

The fringes allow engineers and researchers to observe and analyze the stress distribution and concentration around specific points or structures within the material. It helps them gain insights into how a particular component or material reacts under load and how stress is distributed across its surface.

Photoelasticity is commonly used in engineering, especially in the design and analysis of structures, such as bridges, buildings, and mechanical components. By understanding stress patterns, engineers can make more informed decisions about the material selection and structural design to ensure safety and optimal performance.