Coupled structural-acoustic analysis with substructures

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

This page discusses:

Features tested
Basic coupled structural-acoustic substructure analysis
Coupled structural-acoustic substructure analysis of a box filled with fluid
Coupled structural-acoustic substructure analysis of a simple axisymmetric tire model

ProductsAbaqus/Standard

Features tested

Generation and usage of coupled structural-acoustic substructures.

Basic coupled structural-acoustic substructure analysis

Features tested

The ability to generate a substructure from a simple coupled structural-acoustic model. The substructure is then used in various analysis types.

Problem description

A very simple three-element mesh is used. Two solid (CPE4) elements are tied to a single acoustic (AC2D4) element. The substructure is generated using all eigenmodes that can be extracted, and a substructure load case is generated for a concentrated load. The substructure is then used in a frequency extraction analysis followed by several dynamic procedures (steady-state dynamic response, modal dynamic analysis, and direct-integration implicit dynamic analysis).

A second identical mesh is defined without substructures. The results recovered from the substructure analysis are then compared with the results from the analysis without substructures.

Results and discussion

The results recovered from the substructure analysis are identical to the results from the analysis without substructures.

Input files

substr_small_ac2d4_gen.inp: Coupled structural-acoustic substructure generation input file.
substr_small_ac2d4_use.inp: Coupled structural-acoustic substructures in several dynamic procedures.
nosubstr_small_ac2d4.inp: Input file for the equivalent analysis without substructures.

Coupled structural-acoustic substructure analysis of a box filled with fluid

Features tested

Coupled structural-acoustic substructure generation and usage of a more complex model.

Problem description

The mesh is the same as the box model described in Adaptive meshing applied to coupled structural-acoustic problems. The box is preloaded by a surface-distributed load applied to the interior of the box in a static step. The substructure is generated using a large number of eigenmodes and then used in a frequency extraction analysis followed by several dynamic procedures (steady-state dynamic response, modal dynamic analysis, and direct-integration implicit dynamics).

A second identical mesh is defined without substructures. The results recovered from the substructure analysis are compared with the results from the analysis without substructures.

Results and discussion

The results recovered from the substructure analysis compare very well with the results from the analysis without substructures.

Input files

substr_box_ac2d4_gen.inp: Two-dimensional coupled structural-acoustic substructure generation input file.
substr_box_ac2d4_use.inp: Two-dimensional coupled structural-acoustic substructure used in several steady-state dynamic analysis steps.
nosubstr_box_ac2d4.inp: Input file for the equivalent analysis without substructures.
substr_box_ac2d4_moddyn_gen.inp: Two-dimensional coupled structural-acoustic substructure generation input file.
substr_box_ac2d4_moddyn_use.inp: Two-dimensional coupled structural-acoustic substructure used in direct-integration implicit dynamic and modal dynamic analysis steps.
nosubstr_box_ac2d4_moddyn.inp: Input file for the equivalent analysis without substructures.

substr_box_ac3d4_gen.inp: Three-dimensional coupled structural-acoustic substructure generation input file.
substr_box_ac3d4_use.inp: Three-dimensional coupled structural-acoustic substructure used in several steady-state dynamic response steps.
nosubstr_box_ac3d4.inp: Input file for the equivalent analysis without substructures.
substr_box_ac3d4_moddyn_gen.inp: Three-dimensional coupled structural-acoustic substructure generation input file.
substr_box_ac3d4_moddyn_use.inp: Three-dimensional coupled structural-acoustic substructure used in direct-integration implicit dynamic and modal dynamic analysis steps.
nosubstr_box_ac3d4_moddyn.inp: Input file for the equivalent analysis without substructures.

Coupled structural-acoustic substructure analysis of a simple axisymmetric tire model

Features tested

Coupled structural-acoustic substructure generation and usage.

Problem description

The mesh is the same as the axisymmetric tire model described in Adaptive meshing applied to coupled structural-acoustic problems. The substructure is generated using a large number of retained eigenmodes, and a substructure load case is generated for a concentrated load. The substructure is then used in a frequency extraction analysis followed by several dynamic procedures (steady-state dynamic response, modal dynamic analysis, and direct-integration implicit dynamic analysis).

A second identical mesh is defined without substructures. The results recovered from the substructure analysis are then compared with the results from the analysis without substructures.

Results and discussion

The results recovered from the substructure analysis compare very well with the results from the analysis without substructures.

Input files

substr_smalltire_acax4_gen.inp: Axisymmetric coupled structural-acoustic substructure generation input file.
substr_smalltire_acax4_use.inp: Axisymmetric coupled structural-acoustic substructures used in several dynamic procedures.
nosubstr_smalltire_acax4.inp: Input file for the equivalent analysis without substructures.