Patch test for acoustic elements

This problem contains basic test cases for one or more Abaqus elements and features.

The following topics are discussed:

Elements tested
Problem description
Reference solution
Results and discussion
Input files

ProductsAbaqus/StandardAbaqus/Explicit

Elements tested

AC1D2
AC1D3

ACAX3
ACAX4
ACAX4R
ACAX6
ACAX8

AC2D3
AC2D4
AC2D4R
AC2D6
AC2D8

AC3D4
AC3D5
AC3D6
AC3D8
AC3D8R
AC3D10
AC3D15
AC3D20

Problem description

The meshes used for the acoustic element patch tests are the same as those used for the corresponding heat transfer elements.

Note:

The models are analyzed via steady-state dynamic procedures in which a small frequency, 0.01 Hz, is requested. In Abaqus/Explicit the steady-state results are obtained by performing a long-term transient simulation.

Boundary conditions:

$P = C_{0} + C_{1} x + C_{2} y + C_{3} z$ , where P is the acoustic pressure, $C_{0}$ through $C_{3}$ are arbitrary constants, and x, y, z denote spatial location. Acoustic pressures (DOF 8) are prescribed at every node along the boundary of the mesh.

Reference solution

It is currently not possible to report the pressure gradients for acoustic elements in Abaqus. However, it is possible to compare the acoustic pressures at the interior nodes of the mesh to the values that are analytically calculated from the above expression for P.

Results and discussion

All elements yield exact values of P at the interior nodes of the models.

Input files

Abaqus/Standard input files

ec12afp7.inp: AC1D2 elements.
ec13afp7.inp: AC1D3 elements.
eca3afp7.inp: ACAX3 elements.
eca4afp7.inp: ACAX4 elements.
eca6afp7.inp: ACAX6 elements.
eca8afp7.inp: ACAX8 elements.
ec23afp7.inp: AC2D3 elements.
ec24afp7.inp: AC2D4 elements.
ec26afp7.inp: AC2D6 elements.
ec28afp7.inp: AC2D8 elements.
ec34afp7.inp: AC3D4 elements.
ec35afp7.inp: AC3D5 elements.
ec36afp7.inp: AC3D6 elements.
ec38afp7.inp: AC3D8 elements.
ec3aafp7.inp: AC3D10 elements.
ec3fafp7.inp: AC3D15 elements.
ec3kafp7.inp: AC3D20 elements.

Abaqus/Explicit input files

acousticpatch_xpl_acax3.inp: ACAX3 elements.
acousticpatch_xpl_acax4r.inp: ACAX4R elements.
acousticpatch_xpl_ac2d3.inp: AC2D3 elements.
acousticpatch_xpl_ac2d4r.inp: AC2D4R elements.
acousticpatch_xpl_ac3d4.inp: AC3D4 elements.
acousticpatch_xpl_ac3d6.inp: AC3D6 elements.
acousticpatch_xpl_ac3d8r.inp: AC3D8R elements.