CAA_SURFACE

Type

AcuSolve Command

Syntax

CAA_SURFACE_OUTPUT("name") {parameters...}

Qualifier

User-given name.

Parameters

caa_output (string) [no default]

Qualifier of the CAA_OUTPUT command that outputs quantities integrated over the surfaces defined here.

shape (enumerated) [no default])

Shape of the surfaces in this set.

three_node_triangle or tri3: Three-node triangle.
four_node_quad or quad4: Four-node quadrilateral.

partial_surfaces (array) [no default]

List of surfaces with no references to elements or element sets.

quadrature (enumerated) [=full]

Quadrature rule used for surface integration.

full: Full quadrature.
reduced: Reduced quadrature.

Description

This command specifies a set of surfaces to be used by a CAA_OUTPUT command, given by caa_output, for integrating certain quantities over these surfaces. Surface geometry and integration rules are given here, while the output quantities and related parameters are specified in the referenced CAA_OUTPUT command. For example,

CAA_SURFACE_OUTPUT( "sample surfaces" ) {
   caa_output       = "sample points"
   shape            = four_node_quad
   partial_surfaces = { 1, 1, 2, 4, 3 ;
                        2, 3, 4, 6, 5 ; }
   quadrature       = full
}

defines two surfaces that will contribute to any surface-integrated quantities specified in the CAA_OUTPUT command qualified by "sample_points". If there are no such quantities in the referenced command, then this command has no effect.

The partial_surfaces parameter contains the connectivity of the surfaces. This parameter is a multi-column array, but it does not have the same format as the corresponding parameter in other surface commands, for example, SURFACE_OUTPUT. The number of columns depends on the shape of the surface. For three_node_triangle, this parameter has four columns, corresponding to a unique (within this set) surface number and the three nodes of the surface. For four_node_quad, partial_surfaces has five columns, corresponding to a surface number and the four nodes of the surface. One row per surface must be given. Since there is no parent element definition the three or four nodes of the surface must be ordered around the periphery of the surface. Also unlike other surface commands this command does not support higher-order surfaces, that is, six-node triangles, or nodal quadrature. The nodes contained in the surface connectivity must all be defined in the referenced CAA_OUTPUT command.

The surface connectivity may be read from a file. For the above example, the elements may be placed in a file, such as sample.srf:

1 1 2 4 3
2 3 4 6 5

and read by:

CAA_SURFACE_OUTPUT( "sample surfaces" ) {
   caa_output       = "sample points"
   shape            = four_node_quad
   partial_surfaces = Read( "sample.srf" )
   quadrature       = full
}

A separate CAA_SURFACE_OUTPUT command must be issued for each surface shape and each CAA_OUTPUT command that references surface integrated quantities.