Stress intensity factors for T-butt surface cracks

• Main Author: Tan, Ming Hwa.
• Other Authors: Lie Seng Tjhen
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Civil engineering::Structures and design
• Online Access: http://hdl.handle.net/10356/16080
• Institution: Nanyang Technological University

This study investigates the stress intensity factors for weld toe cracks in a double T-butt joint. There are two main phases that were carried out during the research. Phase 1 of the study involves the double T-butt boundary element meshes modeling from scratch, using the AutoCAD software. Denser count of elements was constructed as it is nearer to the crack tip in order to obtain more reliable results of stress intensity factors. Similar models with different geometric parameter variations were created so as to conduct a more comprehensive parametric study of the effects of each selected varying parameters on the stress intensity factors. The main variations including the attachment footprint ratio, L/T, and also its components, the weld leg length, w and attachment thickness, t. Phase 2 of this study involves the analysis of the results obtained from the varying parameters from the T-butt boundary element meshes. The results of stress intensity factors generated from the boundary element method were then compared towards the calculated stress intensity factor using the exact solution formula. From the stress intensity factors obtained from the double T-butt boundary element model, it can be concluded that the larger the thickness of the attachment plate resulted in a larger magnitude of stress intensity factors. However, regardless of the varying parameters, the stress intensity factors obtained from the boundary element method can be concluded to be well-agreeable to the exact stress intensity factor obtain from the derived equations.