Shell Profiles

The shell profiles are divided into longitudinal frames (or longitudinals for short) and transversal frames (or transversals). They are generated in the Hull module tbchm (Curved Hull Modelling).

The main difference between them is that longitudinals are oriented in the longitudinal direction of the ship whereas transversals are located in or close to frame planes. Otherwise they are organized in the same way.

Common to them both is that a shell profile organizes all the profile parts (called shell stiffeners) that belong to and are referred to by a certain longitudinal or transversal number. Thus a shell profile is either a longitudinal or a transversal and a shell stiffener may be part of either a longitudinal or a transversal.

Shell profiles are identified by an integer number that, in principle, may be selected freely by the designer. The same numbers may be used for both longitudinals and transversals. Longitudinals are normally numbered in steps of 10 with intermediate numbers towards the end of the ship where additional longitudinals have to be inserted. Reference to shell profiles is made via their number and from the local conditions AVEVA Marine will automatically decide from which shell stiffeners data should be fetched, that means, in the modelling work there are never any references directly to shell stiffeners.

Thus, a longitudinal normally consists of a number of shell stiffeners along the same trace curve or along different trace curves that must not overlap along the x-axis. Similarly, transversals consist of shell stiffeners organized along frame curves (or other transversal curves) on the condition that their extension does not overlap when following the curve from the center line towards the deck.

The trace curves of shell profiles may be planar or arbitrary hull curves with double curvature. The actual profile may be planar or twisted (even if the trace curve is planar). Currently a shell stiffener cannot be knuckled.