Create Shell Plate

Purpose:

To create one or several shell plates.

Prerequisites:

The seams and butts defining the shell plate or shell plates must exist.

Instructions:

This function may be used either to create a single shell plate, or several plates generated by a grid of intersecting seams and butts. If a temporary plate has been created via the Developed Plate function in the View menu and this is still selected, this one will be used as input to this function, and the user will not be prompted to pick any seams and butts.

If no plate is selected, in the single plate case, the user is prompted to indicate which seams and butts that define the plate. These must be indicated in a clock-wise direction when seen from the inside of the ship, and the first seam or butt must be the one closest to the aft end of the ship. The plate may consist of three, four or five edges. If the plate has less than five edges, the user must end the picking of seams and butts by Operation Complete.

In case the user wants to create several plates from a seam/butt grid, he will first be prompted to indicate butts from the aft end in direction forward. When the picking of butts has been finished with Operation Complete, the user will be asked to indicate seams from the top in the side shell in direction towards the center line.

When all seams and butts have been picked, the plate data form will appear. This form is used to enter all main plate data such as symmetry information, position number, thickness, material quality, bevelling and excess. If several plates are created at once, Auto Numbering may be checked to automatically set the position number of all plates. Only the position number of the first plate is then entered, and this number will be increased by one for each new plate. If All is checked, the entered plate data will be valid for all plates created. Otherwise, the user must fill in the form once for every plate.

Finally, the plate name form must be filled in to give the plate names. If Add Posno is checked, the position number of a plate will be added at the end of the name given in the Plate Name field. The Auto Name check box is used to automatically form plate names the same way as for hull curves and storable planes. Checking Templates will make plate templates be generated for the plate. These templates are stored together with the plate itself.

Options:

Activating "Options" displays a menu that allows the designer to control the development process in a number of ways:

• If roll axis should be evaluated or not

• Method. Options are contraction (plates to be formed by shrinkage (heating/cooling))

• The raw plate margin

• The direction of strips used in the plate development

• The number of strips

• The tolerance of the spline function used when creating the edges of the developed plate.

Remark:

In addition to these options there is an additional option to control the plate development. Normally the strips are restricted by curves in principal planes. The environment variable SBH_PERP_STRIPS can modify that. If set to DIS the strip curves will be distributed along the longer edge of the plate in the same proportion girth-wise as along the base line of the plate.If set to any other value the strip curves will be perpendicular to the baseline curve.

Result:

One or more new shell plates will be created and selected. The Store function may be used to store the plates on the plate data bank.