33. A New Approach to Calibration of Polycarbonate Material for Photoplastic Studies

Polycarbonate material is calibrated for photoplastic studies using reflection photoelasticity and digital image correlation (DIC) techniques. A modified dog bone specimen is used for easy ordering of photoelastic fringes and to obtain optimum information from a single photoelastic image. The specimen surface is coated with a reflective aluminium spray paint. On top of this a random speckle pattern required for DIC experiment is achieved by spraying black speckles on white background. Both reflection photoelasticity and DIC experiments are performed simultaneously on the dog bone specimen. A maximum principal strain difference of 7 % is measured in the experiment. The photoplastic constant is evaluated by relating the fringe order, N from reflection photoelasticity to the principal strain difference, (ε ₁ − ε ₂) data from DIC.