WHOLE FIELD SHEET-METAL TENSILE TEST USING DIGITAL IMAGE CORRELATION

A whole field sheet-metal tensile test using digital image correlation has been reported. Tensile test data provide valuable information for material characterization. The DIC technique involves the measurement of displacement/deformation by tracking the position of multiple surface points in two consecutive images by using a correlation algorithm. The measurement results clearly demonstrate that the DIC has a great potential for providing whole-field true strain measurement well into the diffuse necking region. The DIC can measure both major strain and minor strain, while the extensometer only obtains the average major strain. It can be used to accurately analyze the initiation of necking, which is almost impossible to achieve with the traditional extensometer technique. This new capability presents the opportunity for the evaluation and optimization of new materials in a precise and accurate manner.