Ductile Failure Simulation of Bending Pipes With Multiple Circumferential Surface Cracks Using an Element-Size Dependent Damage Model

The purpose of this study is to simulate ductile failure of bending pipes with multiple circumferential surface cracks using an element-size dependent damage model. This method is based on the stress-modified fracture strain damage model with stress reduction technique proposed previously by the authors [9,10]. For validation, simulated results using the proposed method are compared with experimental data of Type 304SS pipes performed by Japanese researchers [19]. To calibrate the proposed method, pipe test data with a single surface crack were compared with simulated results using the damage model. Based on the calibrated damage model, the pipe tests with multiple circumferential surface cracks were simulated. The bending moment at both crack penetration and coalescence were calculated from the FE damage analysis. These results were compared with the experimental results. In spite of its simplicity, the results show that proposed method can simulate ductile failure behavior of bending pipes with multiple circumferential surface cracks.