AN INVESTIGATION ON RELIABILITY OF FINITE ELEMENT MODELS IN PREDICTING CAPACITY OF TUBULAR JOINTS

Circular tubular sections are widely used in design and construction of fixed offshore platforms. Code-based loadcarrying capacity of tubular joints are dominantly proposedaccording to experimental tests. However, due to high costs and difficulties attributed to the development of experimental tests, experimental database for predictingcapacity of tubular joints are limited. The engineering community needs to be supported with more insight into how reliable FE models can be developed for predicting the load-carrying capacity of tubular joints. FE models can enhance the database for future code-based capacity formulations. Moreover, FE models can be regarded as a promising tool for evaluating existing fixed offshore platforms. Because, effects of local joint flexibility and brace interaction are automatically incorporated in such models. In this paper, a nonlinear FEmodel is carefully constructed using shell elements in ANSYS [1] for investigating the pros and cons of such models in evaluating the capacity of unreinforced tubularT-joints subjected to the actions of tensile, compressive and in-plane bending loads of the brace. Finally, a brief discussion on the effects of boundary conditions of thechord on capacity of the joints is presented. The results from FE models shall be compared with recommendations of latest edition of API standard [2].