Simulation of Ductile Fracture in Pipeline Steels Under Varying Constraint Conditions

This study has two major objectives: (1) to study the effect of non-singular T-stress (or constraint) variations on crack tip opening angle (CTOA) of pipeline steels using modified boundary layer (MBL), and (2) to simulate ductile crack propagation in pipeline steels using drop weight tear test (DWTT) and comparing these FE simulations with experimental results. The calibration of various CZM was done using different traction-separation laws. Mainly, three models named SSY, MBL, and DWTT were used for three sets of materials: TH steel, C2 steel and C4 steel. The crack tip opening angles were obtained from all the FE simulations (ABAQUS-Finite element program).