Difference between revisions of "SC Hull"

Latest revision as of 11:03, 6 October 2009

Surfaces and expansions[edit]

How to position in the drawing

Templates[edit]

Templates are required for plates which need mechanical processing (bending or forming) to obtain the desired shape.

We need templates in the following situations:

• Single curvature (bending) with constant radius - no template required, give bending info on plate.
• Single curvature (bending) without constant radius - 1 template required.
• Double curvature (forming) - minimum 3 templates required.

Template types

• Bow Fashion - for plates which are on the center line and have symmetry around the center line (for example a bow cone)
• Standard - all other plates:
  • Create the templates on the reference lines, as perpendicular to the surface as possible, or if this is not applicable:
  • Use Auto-Level

Template label

• Plate Name
• Marking Line Name
• Bracket Angle

Template name is plate name + reference line name or, when using Auto-Level, plate name + T1 (T2, T3, etc.)

Template style is Plate

Edge margin 50mm

Check list SC Hull[edit]

• Expansion settings
  • General
    • Expansion Option Find Best Strain Fit
    • Stretch Expanded Plate None
    • Text size 50
    • Roll Lines None
  • Add Stock
    • None
  • Templates
    • Show label Plate name, Marking Line Name
    • Label size 50
    • Place labels on templates
    • Show on Plate Surface
    • Show Alignment Icon, Size 50
    • Surface Side Mold Side
    • Type Bow Fashion for templates with symmetry at CL, or
    • Type Standard for templates with non-symmetry at CL, then
    • use reference lines for templates
    • use Auto-Level templates only when:
      • the shape is not sufficient defined with reference lines
      • the angle of the templates at the plate becomes to small
    • Style Plate
    • Template name is plate name + reference line name, or
    • Template name is plate name + marking line name (T1, T2, etc.)
    • No Edge Margin
    • Indicate sightline angle
    • Sightline arrow direction to CL or UP
    • Bow fashion CL template to have an arrow indicating the top - keep inside template

File import and preparation before expansion[edit]

• 1.Set Surface Properties:
  • a.Name required for templates only
  • b.correct Stock properties
  • c.correct Throw
  • d.Mode ‘Solid’’
  • e.solines ‘None’
  • f.colour conform stock
  • g.correct Markside
• 2.Create Cut Sections (settins as for Reference Lines in Structure)
• 3.Create Marklines, settings (Edit Labels):

• 4.Name at least the following Marklines:
  • a.deck at side
  • b.tankt at side
• 5.Split surfaces when they do not fit the stock

Note: do not toggle on the labels for the solids since they will appear also in the 3D solid model in the unit.

Plate expansion without templates[edit]

When the surface has single curvature which is not too strong, then templates are not required.

• Plate Expansion Settings:

• With plate strains >1% ShipConstructor sometimes becomes inaccurate, check by measuring framelines and/or contourlines and compare them with the same lines in Rhinoceros.
• Toggle labels ON for Sections of the expanded surface
• Arrange the expanded plates for a suitable lay out in the Approval drawing.

Plate expansion with standard templates[edit]

When the surface has double curvature or single curvature but strong, templates are required.

• Templates must be concave, when the surface is convex, the Surface Side for the templates must be Thick Side instead of Mold Side.
• When the Surface Sside is Mold Side, the text ‘Contra Templates’ must be added to the plate and it’s templates (in CrvPlate group).
• Alignment icons must all indicate in the same direction within a project.
• Plate Expansion Settings:

Guidelines

• The stonger the curvature, the more templates required
• Use framelins for the templates as much as possible
• With strong curvature, the distance of the template to the end of the surface should not exceed 100mm, create additonal sections if required
• Names for additonal sections for templates to be ‘T01’, ‘T02’, etc.

Plate expansion with bow fashion templates[edit]

Use bow fashion templates for symmetrical surfaces with the neutral axis on the centerline, for example flared bows.

• See ‘Plate expansion with standard templates’
• Plate Expansion Settings:

Check

• Plate and Section names are toggled ON for expanded plate
• Templates have Plate Name, Marking Line Name and Bracket Angle
• Templates are concave
• Alignment icon all indicate in same direction
• No double sightlines on plate (occur when the same plate is expanded several times)
• Presence of Orientation Icon
• Aiignment icon indicates correct side (especially with templates at Thick Side, ShipConstructor sometimes indicate wrong)
• Several dimensions of expanded plate, especially with a lot of curvature (framelines, contour) and see if they match in Rhino.
• When the strain indicates that the plate will shrink, meaning it will be too short after forming, stock must be added in the Curved Plate Group.