Structural analysis of main deck of RoPax vessels: A finite element analysis approach combining hull girder loads and local loads for buckling assessment

Sammanfattning

This thesis develops a finite element analysis-based methodology for assessing the buckling behavior ofvehicle deck structures in RoPax vessels under combined global and local loading conditions. Theproposed approach combines rule-based calculation of hull girder loads, midship section modeling, sub-modeling, and the application of local wheel loads.The methodology is demonstrated on Deck 3 and Deck 5 of a reference RoPax vessel. The global hullgirder loads are calculated according to DNV formulations and applied to a finite element model of themidship section. The resulting boundary response is then transferred to refined local deck models, wherelinear buckling analyses are performed under both pure hull-girder loading and combined hull-girder andwheel loading conditions.The results show that both deck structures maintain sufficient margins against buckling under theinvestigated design load cases. For Deck 3, the influence of the hull girder load is limited due to its locationclose to the neutral axis. For Deck 5, the top plate panels are identified as the main buckling-sensitiveregions. The local wheel load reduces the buckling load multiplier and shifts the critical deformationtowards the loaded areas; however, the structures remain within a safe range.