Design recommendations for container ship side-shell structure under fatigue strength assessment

The aim of the work is to evaluate various designs in order to arrive at some guidelines for choosing a good standard design by means of a fatigue damage analysis in the connection between longitudinal stiffener and transverse web frame on container ship side-shell structure located in the upper wing torsional box. Design proposals and recommendations are developed, based on numerical and experimental analysis, which allow, from different structural configurations formed by combinations between cut-outs and collar plates, to establish more and less adequate structural designs in one of the ships with the greatest future projection. In the first phase, the cut-out without influence of the longitudinal stiffener is studied and the stress state and fatigue assessment are determined. In the second phase, the longitudinal stiffener is taken into account under the presence of the collar plate in the model and different geometrical alternatives (thickness, ducktail, overlap and radius of curvature) and their influence on the determination of stress and fatigue life are studied. From the different configurations, the most appropriate combination is established and structural solutions are proposed in order to improve the design. •The structural interaction on the longi-web connection in the upper wing torsional box was determined.•A local model of each geometry was carried out to validate the numerical results.•The fatigue damage obtained from the design conditions was evaluated by geometric modifications.