Engineering Commons^™

Investigation Of Ductile Crack Growth And Normalization Method For Se(T) Specimen Using Finite Element Analyses, Cheng Qian

Electronic Thesis and Dissertation Repository

The fracture toughness resistance curve (e.g. J-R curve) is widely used in integrity assessment and strain-based design of oil and gas pipelines with respect to planar defects (i.e. cracks). This thesis includes two-dimensional (2D) and three-dimensional (3D) finite element analyses (FEA) of ductile crack growth of X80-grade pipeline steel based on the Gurson-Tvergaard-Needleman (GTN) constitutive model, and investigation of the normalization (NM) method to generate the J-R curve for the single-edge tension (SE(T)) specimen.

First, the GTN model implemented in the computational cell is adopted in the commercial software ABAQUS to calibrate the micromechanical parameters for the pipeline steel. Subsequently, …

Numerical Studies For Improving Fracture Toughness Resistance Curve Testing Using Single-Edge (Notched) Tension Specimens, Yifan Huang

Electronic Thesis and Dissertation Repository

The fracture toughness resistance curve, i.e. the J-integral resistance curve (J-R curve) or the crack tip opening displacement resistance (CTOD-R) curves, is widely used in the integrity assessment and strain-based design of energy pipelines with respect to planar defects (i.e. cracks). This thesis deals with issues related to the experimental determination of the J(CTOD)-R curves using the newly-developed single-edge (notched) tension (SE(T)) specimens. In the first study, the plastic geometry factor, i.e. the η_pl factor, used to evaluate J in a J-R curve test based on …