Stress Concentration Factor and Fatigue Life Evaluation in offshore tubular KT-Joints

Aidibi, Ali (2020) Stress Concentration Factor and Fatigue Life Evaluation in offshore tubular KT-Joints. [Laurea magistrale], Università di Bologna, Corso di Studio in Offshore engineering [LM-DM270] - Ravenna, Documento full-text non disponibile
Il full-text non è disponibile per scelta dell'autore. (Contatta l'autore)


In the last few decades, offshore field has grown fast especially after the notable development of technologies, explorations of oil and gas in deep water and the high concern of offshore companies in renewable energy mainly Wind Energy. Fatigue damage was noticed as one of the main problems causing failure of offshore structures. The purpose of this research is to focus on the evaluation of Stress Concentration Factor and its influence on Fatigue Life for 2 tubular KT-Joints in offshore Jacket structure using different calculation methods. The work is done by using analytical calculations, mainly Efthymiou’s formulations, and numerical solutions, FEM analysis, using ABAQUS software. As for the analytical formulations, the calculations were done according to the geometrical parameters of each method using excel sheets. As for the numerical model, 2 different types of tubular KT-Joints are present where for each model 5 shell element type, 3 solid element type and 3 solid-with-weld element type models were built on ABAQUS. Meshing was assigned according to International Institute of Welding (IIW) recommendations, 5 types of mesh element, to evaluate the Hot-spot stresses. 23 different types of unitary loading conditions were assigned, 9 axial, 7 in-plane bending moment and 7 out-plane bending moment loads. The extraction of Hot-spot stresses and the evaluation of the Stress Concentration Factor were done using PYTHON scripting and MATLAB. Then, the fatigue damage evaluation for a critical KT tubular joint based on Simplified Fatigue Damage Rule and Local Approaches (Strain Damage Parameter and Stress Damage Parameter) methods were calculated according to the maximum Stress Concentration Factor conducted from DNV and FEA methods. In conclusion, this research helped us to compare different results of Stress Concentration Factor and Fatigue Life using different methods and provided us with a general overview about what to study next in the future.

Tipologia del documento
Tesi di laurea (Laurea magistrale)
Autore della tesi
Aidibi, Ali
Relatore della tesi
Correlatore della tesi
Corso di studio
Ordinamento Cds
Parole chiave
Stress concentration factor; Fatigue Damage; Hot spot stresses; Analytical solutions; Numerical solutions; Offshore jacket structure
Data di discussione della Tesi
12 Ottobre 2020

Altri metadati

Gestione del documento: Visualizza il documento