This paper deals with a practical method for estimating the weight of ro-ro deck structures. Preliminarily, the procedures for assessing the scantlings of platings, ordinary stiffeners and primary supporting members subjected to wheeled loads, are presented, in order to point out the parameters that influence the deck weight, such as ordinary stiffener spacing, transverse spacing, number of girders, web height of primary supporting members. The strength check of platings is rule based, while ordinary stiffeners are schematized as continuous beams; concerning the primary supporting members, instead, the direct scantling procedure, proposed in a previous paper, is adopted, schematizing the deck as an orthotropic plate with clamped boundary conditions in correspondence of the aft and fore bulkheads and the ship sides, in order to take into account the interaction of the two orthogonal beam sets. Some design charts are presented in order to determine the influence of the previously defined parameters on the deck weight or, similarly, on its equivalent thickness, spreading the stiffener and primary supporting member weight on the deck area. Finally, two numerical applications, relative to a Ro-ro PANAMAX ship, are presented, in order to evaluate the capability of the proposed technique.
A procedure for estimating the structural weight of ro-ro decks
PISCOPO, VINCENZO
2009-01-01
Abstract
This paper deals with a practical method for estimating the weight of ro-ro deck structures. Preliminarily, the procedures for assessing the scantlings of platings, ordinary stiffeners and primary supporting members subjected to wheeled loads, are presented, in order to point out the parameters that influence the deck weight, such as ordinary stiffener spacing, transverse spacing, number of girders, web height of primary supporting members. The strength check of platings is rule based, while ordinary stiffeners are schematized as continuous beams; concerning the primary supporting members, instead, the direct scantling procedure, proposed in a previous paper, is adopted, schematizing the deck as an orthotropic plate with clamped boundary conditions in correspondence of the aft and fore bulkheads and the ship sides, in order to take into account the interaction of the two orthogonal beam sets. Some design charts are presented in order to determine the influence of the previously defined parameters on the deck weight or, similarly, on its equivalent thickness, spreading the stiffener and primary supporting member weight on the deck area. Finally, two numerical applications, relative to a Ro-ro PANAMAX ship, are presented, in order to evaluate the capability of the proposed technique.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
