Measurement of Luders band of cast iron material based on 3D-DIC de-correlation effect

In the material tensile test, the fracture usually starts from generation of the Luders band. The Luders band can be measured by strain, but the conventional strain gauge cannot be used to measure due to undetermined position of the Luders band. The fracture phenomenon can be monitored by the full field strain measurement. However, the common full-field measurement method must cause delay because of the excessive calculation amount. Hence generation of the fracture cannot be measured in real-time. The 3D-DIC method is an efficient way of the full field non-contact measurement. By simplifying the 3D- DIC method and transforming the object of interest, this paper can focus on the generation of large strains, greatly reduce the amount of calculation and monitor the production and development of the Luders band in real time at last.