ABSTRACT
The paper discusses and highlights the basic challenges and results in a structural design and analysis of large RORO ship of 5500 lane meters (Lm) capacity. From the structural point of view RORO ships are multi-deck ships characterized with the absence of transverse/longitudinal bulkheads in an upper part. This kind of structure topology generates two main structural challenges: (1) Longitudinal strength; hull girder longitudinal strength, due to large openings in the upper part of side shell; (2) Transverse/racking strength; due of absence of transverse bulkheads in superstructure and large tween-deck heights. The direct strength calculation has been carried out according to Lloyd Register (LR) Structural Design Assessment (SDA) for RORO ships. Global full ship FE model and detail fine mesh local models were developed to evaluate yielding, buckling and fatigue criteria according to SDA requirements. Challenges to fulfill the SDA requirements regarding implementation of load cases and evaluation criteria have been discussed.
