Plane Panel

The panels are divided into two types with entirely different principles: plane panels (in the internal structure of the ship) and curved panels in sculptured surfaces. Since they are so different they will be described in separate paragraphs. This paragraph concentrates on plane panels. For recommendations regarding panel names, see About Naming.

The panel is The model object of the internal structure, that means, all modelling of the planar internal structure must be done via plane panels. The panel is also the level on which model information is stored in the data bank, for example, a plate part or a stiffener can only be made part of the product model as included in a panel.

A panel may range in size and complexity from small bracket-like panels consisting of only a plate to big decks containing hundreds of parts. However, there are two conditions that must be fulfilled:

1. The ordinary plates of the panel must be located in one plane (for the special case of knuckled panels, see below).

2. It must be possible to create a closed outer contour of the panel. Thus it is normally inconvenient to create a complicated web ring structure as one panel.

The panel is a kind of "container" object. Panels consist of a number of parts, mostly implicitly stored, and a number of "features" that are required for the creation of the parts and for their adaptation to the production requirements. Thus, the hull structure data bank does not contain any explicit parts - they are realized in an automatic parts generation process when a certain region, for example, a block or a panel, is ready for production. With this definition parts extracted for production are not considered to be part of the actual (and implicit) model.

The parts that a panel may consist of are plates or profiles.

Depending on how they are generated and used the part types can be further divided into sub-types.

The plates may be:

• Ordinary plates in the mould plane of the panel

• Bracket plates

• Clip (or collar) plates.

The profiles may be divided into the following types that are relevant mainly in the modelling phase (this classification is less relevant when it comes to production).

• Stiffeners (on the panel itself or on brackets)

• Welded flanges (often called face plates) (on the panel itself or on brackets)

• Pillars

In order for the parts to get all the information required to make them accurate and ready for production a panel may be generated with a number of features that contribute with information when the parts are extracted for production.

Examples of features in plane panels are:

• An outer contour of the panel as a whole,

• Seams that together with the outer contour will define the plate parts,

• Plate thickness and material quality,

• Bent flanges that will affect the geometry of plate parts,

• Bevel along the weld traces in edges of both plates and profiles,

• Profile characteristics and end cutting of profiles,

• Holes, notches and cutouts in both plates and profiles,

• Excess (overmaterial, green material),

• Swedging (small corrugation),

• Shrinkage compensation.

The picture below shows a panel with some parts of different types and with some types of features. The figure contains both a symbolic view of the panel (used in traditional working drawings) and a 3D isometric view of the same panel.

Figure 2:2. Example of a simple panel

The parts defined in a panel are normally not stored with their full geometry. As an example the plates are implicitly defined by reference to the outer contour of the panel and to seams that restrict them. Explicit information is the plate thickness and the material quality. When released as an explicit part different features will affect the geometry so that it becomes apt for production. for example,:

• Bevel along seams and the outer contour will influence both the edge shape and the plate geometry, for example, because of required bevel gaps.

• Holes, notches and cutouts will create open or closed "openings" in the plate geometry.

• If the plate is flanged the plate geometry will be expanded to include the folded flange.

• If the plate is swedged the plate will have to be expanded to compensate for the swedging.

• If excess is defined the plate will be made larger.

• If shrinkage compensation is asked for the plate will be slightly expanded to compensate for the shrinkage.

• Etc..,

• Finally the part will automatically get marking lines for all parts welded against it.

Thus the implicit model contains all the information necessary to make the plate become a "real" part for production.