Resumo:
This paper presents a study of the distribution of stresses and strains acting on a
prismatic ferry that makes use of an idealized composite [1] to naval employment. The
structural arrangement of the ferry is minimized in order to achieve the limit of the minimum
dimensions and thicknesses able to resist deformation and maximum stresses. This minimum
structural arrangement was chosen in order to study the limits of the recently developed
material. Calculation of stresses and strains on the vessel is conducted with the aid of a
software-based on Finite Element [2] and [3] method. In order to proceed to the stresses and
strains calculations the ferry was subjected to different loading conditions: one of hogging and
another of sagging, assuming the same load capacity in both situations. The basic structural
arrangement adopted in a base composite element is formed by two faces and an expanded
polystyrene core. Equally spaced shear webs connect both laminated faces. These
reinforcements and both faces are laminated with fiber glass impregnated with epoxy resin. In
defining the minimum dimensions of the elements a rule of thumb [4] is used in order to start
to search for the modeling of the minimum geometry and generate the results. Results of
stress distribution and deformation of the hull structure are presented. It is also computed the
total weight of the structure in order to compare with another structural weight. So, these
same dimensions previously defined for the ferry are also used to define a structure based in a
core of Divinycell® to compare the total structural weight. At last, it is concluded that the
present structure [1] has a weight consistent with the lower density Divinycell, but with a
much lower price than the composite structure cored with Divynicell®
