FINITE ELEMENT ANALYSIS OF CYLINDER-TO-CYLINDER INTERSECTIONS

Cylinder-tocylinder intersections are common configurations in structural components for off-shore structures. Studies, previously carried out, show that most failures start at intersection region. Such failures are due to a number of factors; primary among them is the inability of existing design methods to adequately define the stresses at the intersection region. The present paper is concerned with the finite element analysis of class of T joints subjected .to external mechanical loads. First, the existing finite element models used to solve shell intersection problems are reviewed. Discussions are made on the suitability of these models to idealize the complicated 3-d behaviour of the intersection region. To solve the T joint p-oblem, a fiite element model based on the flat plate element found in the general computer program SAP90 are utilized. The mesh used is generated automatically by a special computer program from description of joint geometry and degree of mesh refinement desired. Detailed information on the stresses at and around the intersection line has been provided in the paper. The results obtained indicate that stresses are changing rapidly at the intersection region and highly membrane and bending stress concentration factors are obtained at the intersection line. Comparison of analysis results with experimental data shows a good agreement and indicates the suitability of the present procedure as an efficient and highly accurate design tool. Moreover, and due to the time saving made by using the "mesh generation" technique, the finite element' method can claim its right position as the most suitable design tool for this problem.