This paper is concern with the modelling, mesh generation and analysis of tubular T-joints containing through-thickness crack which can be of any length and location along the intersection curve between the brace and the chord. A mesh generating procedure for tubular joint with arbitrary through-thickness crack is introduced based on the concept of crack surface. The finite element model is analyzed and the results are used to evaluate the stress intensity factor (SIF) of the crack. The SIF validation results demonstrate that the model is reliable.
For offshore structure, fatigue assessment is often the main concern during the structure's life. As the result of fabrication defects or damage in service, cracks exist in nearly all tubular joints. When the fatigue cracks are detected by in-service inspections, the residual life of this fatigue damaged structure have to be assessed using the fracture mechanics approach. The finite element (FE) method is a powerful numerical analysis tool and has been used widely to analyze different types of welded tubular joints. In recent years, in order to get detailed analysis of the fracture and crack growth behaviors to predict the remaining life of a cracked joint, more and more attention has been paid to the study of fracture behavior of cracked tubular joints using the finite element method. Stress intensity factor (SIF) is often used as a design parameter to determine the nature of the fracture process and can be used to determine the residual life of a fatigue damaged structure. For weld toe cracks in tubular joints, it is an extremely difficult task to determinate accurately the SIFs along the crack front because the geometry of the joint with the crack is very complex and, hence, difficult to model. Recently, many modelling techniques have been proposed to overcome this problem.
