Measurement of Strain Localization in a Tensile Test Using Full Field Optical Technique - Digital Speckle Correlation

This paper presents digital speckle correlation technique to study the strain at the macroscopic level during a tensile test. Digital Speckle Correlation (DSC) is a full-filed and non-contacting optical technique. It offers a significant advantage over conventional techniques such as extensometer for tensile test of materials. It has a high sensitivity and accuracy and thus helps in determining the true mechanical properties of the material for a better understanding of component behavior. From the measured data, we see that the accuracy of the system is sufficient enough to track the initiation and development of strain concentration in the necking region by computing the strain contours in full field environment. True Strain-stress data is presented with a comparison of the measured data with the traditional method. Initiation of the necking region has been identified using the full field data measured.