# VAO_ELEMENT_OUTPUT

Specifies a set of elements for vibro-acoustics integrated-element output.

AcuSolve Command

## Syntax

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

User-given name.

## Parameters

coordinates or coord (array) [no default]
An array of sample points used to construct the elements defined by the elements_array parameter. Each row contains a unique identification number and the x, y and z coordinates of a point in the global xyz coordinate system.
gap (real) >=0 [=0]
Tolerance for sample points falling outside of all elements.
shape (enumerated) [no default]
Topology of the elements in this set.
four_node_tet or tet4
Four-node tetrahedron.
five_node_pyramid or pyramid5
Five-node pyramid.
six_node_wedge or wedge6
Six-node wedge (prism).
eight_node_brick or hex8
Eight-node brick (hexahedron).
elements (array) [no default]
List of element connectivity.
quadrature (enumerated) [=full]
Quadrature rule used for volume integration.
full
Full quadrature.
reduced
Reduced quadrature.

## Description

This command specifies a set of elements for the element-integrated vibro-acoustics output data. Element geometry and integration rules are given here, while the output quantities and related parameters are specified in the VAO_OUTPUT command. For example,
VAO_ELEMENT_OUTPUT( "sample elements" ) {
coordinates = Read( "sample.crd" )
elements    = Read( "sample.cnn" )
shape       = eight_node_brick
quadrature  = full
}

defines the vibro-acoustic output on a set of elements specified by sample.cnn.

A set of sample points is specified by the coordinates parameter, which is a four-column array corresponding to an identification number and the x, y and z coordinates of each sample point, one row per point. The identification number may be any arbitrary but unique (within the set) integer. Negative numbers are acceptable. The coordinates are in the global xyz coordinate system. This is the same format as the coordinates parameter of the COORDINATE command, but the sample points do not have to be a subset of the nodal coordinates nor related to them in any other way. The coordinates parameter is mandatory. Within AcuPrep, an element is found for each sample point and interpolation shape functions are computed. If a sample point falls outside all fluid elements, then the closest element face is found, up to a distance specified by gap. An error is issued if no element is found.

The elements parameter defines the element connectivity and has the same format as the corresponding parameter in ELEMENT_SET command. However, the elements defined here need not have any relationship to any other elements or element sets in the CFD model. Unlike ELEMENT_SET this command does not support higher-order elements (that is, ten-node tetrahedra) or nodal quadrature.