Structural desig of midship section of Ro-Ro ship

Tema ovog rada je projektiranje konstrukcije glavnog rebra broda za prijevoz automobila i kamiona (Ro-Ro). Proračun uzdužne konstrukcije proveden je po pravilima klasifikacijskog društva Bureau Veritas koristeći program MARS. Posebna pažnja je posvećena dimenzioniranju paluba opterećenih kotačima vozila. Za njih je provedena analiza senzitivnosti mase uzdužnih elemenata konstrukcije u ovisnosti o razmaku poprečnih okvira i razmaku uzdužnjaka. Ispitane su 24 varijante razmaka okvira i uzdužnjaka s ciljem dobivanja optimalne varijante koja rezultira minimalnom masom. Za varijantu minimalne mase i varijantu zadanu predloškom napravljeni su 3D parcijalni modeli u programu MAESTRO kako bi se napravila analiza metodom konačnih elemenata. Analiza je napravljena za četiri različita slučaja opterećenja, te su nepodobni elementi strukture redimenzionirani tako da zadovolje sve kriterije strukturne podobnosti. Naposljetku, napravljena je usporedba masa između dva modela nakon redimenzioniranja strukture.The theme of this paper is structural design of midship section of a Roll-on/Roll-off (Ro-Ro) ship for transport of cars and trucks . Defining of the longitudinal construction elements was done in accordance with the rules of Bureau Veritas classification society using software MARS. Particular attention was given to the defining of decks under wheel load. For them, a sensitivity analysis of mass of longitudinal construction elements in dependence of the web frame spacing and longitudinals spacing was performed. Twenty four variants of the web frame spacing and longitudinals spacing were studied in order to obtain an optimal variant resulting in minimal mass. For the variant of minimal mass and the variant given by the template, 3D partial models were created in software MAESTRO in order to conduct a finite element method analysis. The analysis was made for four different load cases and inadequate structural elements were redefined in order to meet all the structural adequacy criteria. Finally, the comparison of a structural mass was made between the two variants after redefining the structure