True Stress-Strain Curves Test and Material Property Analysis

True stress-strain curves of two natural gas pipeline steels were studied using the 3D-DIC (digital image correlation) technique. During the test, the steels are continuously strained hardening up to the fracture, and true stress-strain curves are obtained. It is found that the true stress increases with strain after necking, which is notably different from the results obtained by the conventional method. Using the FEM model, the true stress-strain curves were validated. Based on the material¿s inherent properties, the material property analysis is implemented. The content of this book could improve the understanding of material properties, and learn more about testing methods. The material properties were the basis for the Engineering Critical Assessment of pipeline. So the data and method was very important for the integrity and safety assessment.