GEOMETRY SURFACE 4SIDES [snam] [+mid1] lnam1 [+mid2] lnam2 [+mid3] lnam3 [+mid4] lnam4 [elt]

            

This command is used to create a 4-sided surface from 4 lines. An extended form of the command allows the automatic creation of combined lines.

snam = name of the surface, used for later references to the surface.

+mid = names of lines defining new combined lines.

lnam = names of lines, or line combinations. The sides must be given in consecutive order but may start at any side and go in either direction.

elt = element type on the surface. A default element type of QU4 will be assumed if `elt' is omitted. Refer to command MESHING TYPES for a detailed description.

In the case where no new combined lines are defined in the command, FEMGEN will create a surface based on the four lines specified. A line may be a simple line or a combined line.

Where new combined lines are defined in the command, either cursor picking or keyboard input can be used to distinguish between `last lines' and `mid-side lines'. With the cursor, the left button is used to specify a last line and the middle button (or right button on a two button mouse) is used to specify a mid-side line. With the keyboard, a last line is typed normally while a mid-side line is immediately preceded by a `+' (plus sign).

Each side is identified by its last line, which enables simple termination of the command. Thus the definition of a surface is completed by specifying the last line of the last side.

Return Level: GEOMETRY SURFACE

Examples:

1.

GEOMETRY SURFACE 4SIDES S1 L1 L2 L3 L4

Create a four-sided surface S1 with edges L1, L2, L3, and L4 with the default element type QU4.

2.

GEOMETRY SURFACE 4SIDES S1 L1 L2 L3 L4 QU8

Create a four-sided surface S1 with edges L1, L2, L3, and L4 with element type QU8.

3.

GEOMETRY SURFACE 4SIDES S1 +L1 +L2 L3 L4 L5 +L6 L7

Create a surface S1 with 4 sides, the first of which is a combined line comprising the lines L1, L2 and L3; the second side is the line L4; the third side is the line L5; and the fourth side a combined line comprising the lines L6 and L7.

See also the following commands

'LABEL GEOMETRY SURFACES'
'UTILITY DELETE SURFACES'
'UTILITY TABULATE GEOMETRY SURFACES'
'VIEW GEOMETRY'