| Title |
Numerical Assessment of Tensile Strain Capacity for X80 Line Pipe Using GTN Model |
| Authors |
윤영철(Yoon, Young-Cheol) ; 김기석(Kim, Ki-Seok) ; 이재혁(Lee, Jae Hyuk) ; 조우연(Cho, Woo-Yeon) |
| DOI |
https://doi.org/10.12652/Ksce.2016.36.6.0979 |
| Keywords |
변형률 기반 설계;X80 라인파이프;인장 변형성능;비선형 유한요소 해석;GTN 모델 Strain-based design;X80 line pipe;Tensile strain capacity;Nonlinear finite element procedure;GTN model |
| Abstract |
This study presents a nonlinear finite element procedure involving a phenomenological model to validate the tensile strain capacity of the X80 line pipe developed for the strain-based design purpose. The procedure is based on the Gurson-Tvergaard-Needleman (GTN) model, which models nucleation, growth and coalescence of void volume fraction occurred inside a metal. In this study, the user-defined material module (UMAT) is implemented in the commercial finite element platform ABAQUS and is applied to the nonlinear damage analysis of steel specimens. Material parameters for the nonlinear damage analysis of base and weld metals are calibrated from numerical simulations for the tensile tests of round bar and full thickness specimens. They are then employed in the numerical simulations for SENT (Single Edge Notch Tension) test and CWPT (Curved Wide Plate Test) and in the simulations, the tensile strain capacities are naturally evaluated. Comparison of the numerical results with the experimental results and the conventional empirical formulae shows that the proposed numerical procedure can fairly well predict the tensile strain capacity of X80 line pipe. So, it is readily expected to be effectively applied to the strain-based design procedure. |