A STRESS ANALYSIS OF CIRCULAR CYLINDRICAL SHELL INTERSECTIONS, INCLUDING THE INFLUENCES OF REINFORCEMENT, CYCLIC PLASTICITY AND FATIGUE

The intersection of cylinders is an unavoidable element in many engineering installations such as nozzle to cylinder connections in nuclear reactors or pressure vessels, pipe intersections in offshore platforms etc. The region of intersection presents a sharp geometric discontinuity in the structure which produces a stress field with very high stress concentration.;A unified in depth study of the behavior of cylinder intersections is presented in this document. This study consists of numerical evaluations of the stress fields in the vicinity of the cylindrical shell intersections. Included in the study are variations of reinforcement configurations around the curve of intersection, variations of nozzle to cylinder diameter ratios, variations of angles of intersection, and cyclic plasticity. The finite element method is employed for this stress analysis. An algorithm is developed for an automated mesh generation covering the region of the cylinder intersection. A kinematic strain hardening material model is formulated for application to cases with cyclic plasticity. The results of the nonlinear analysis are incorporated with existing numerical techniques to predict the fatigue life of the components involved.