Miscellaneous submodeling tests

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

This page discusses:

Using different procedures between the global model and the submodel
Acoustic-to-structure submodeling
Intersection-only submodeling
Node-based submodeling using field import
Beam-to-surface submodeling

Products Abaqus/Standard Abaqus/Explicit

Using different procedures between the global model and the submodel

Elements tested

CAX4R
CPS3
CPS4R
C3D8R
C3D8RT

Features tested

The submodeling capability is applied to different procedures between the global model and the submodel. The global procedure can be performed in Abaqus/Explicit and the submodel procedure in Abaqus/Standard or vice versa. When appropriate, a submodel boundary condition is used to adjust the time variable of the driven nodes to match the submodel analysis step time.

Problem description

The first set of problems is based on the models that are described in Two-dimensional continuum stress/displacement submodeling. In the examples used here, however, each analysis has a second compression step. The global analysis is performed in Abaqus/Explicit, and the submodel analysis is performed in Abaqus/Standard. The step times of the analyses are different. Since the Abaqus/Explicit job is quasi-static and the Abaqus/Standard job is static, the step time from the global model is scaled to match the step time period of the submodel analysis.

The second set of tests is based on the models that are described in Coupled temperature-displacement submodeling. The global model uses C3D8R elements, and the problem is a stress/displacement analysis. The submodel uses C3D8RT elements, and it is a coupled temperature-displacement analysis. The validity of this submodeling analysis is based on the fact that the temperature effects are relatively small at the submodel level.

The last set of problems tests the direct-integration implicit dynamic procedure with submodeling. The global analysis is performed in Abaqus/Standard, and the corresponding submodeling analysis is performed in Abaqus/Explicit, or vice versa.

Results and discussion

All of the driven variables are interpolated correctly from the global analysis. Figure 1 shows the effect of the TIMESCALE parameter on the amplitude formed at the driven nodes. If the analyses have the same step time, the two curves will be identical.

In the second and third set of tests the results agree well between the global model and the submodel.

Input files

submproc_g_quasi2static_xpl.inp: Global, TIMESCALE parameter; Abaqus/Explicit quasi-static analysis.

submproc_s_quasi2static_std.inp: Submodel, TIMESCALE parameter; Abaqus/Standard static analysis.
submproc_s_quasi2static_std_sb.inp: Submodel, TYPE=SURFACE parameter; Abaqus/Standard static analysis.

submproc_s_quasi2st_2nd_std.inp: Submodel, TIMESCALE parameter; second-order elements; Abaqus/Standard static analysis.

submproc_g_dyn2tempdisp_xpl.inp: Global stress/displacement analysis; Abaqus/Explicit analysis.

submproc_s_dyn2tempdisp_xpl.inp: Submodel coupled temperature-displacement driven by the stress/displacement model; Abaqus/Explicit analysis.

submproc_s_dyn2tempdisp_std.inp: Submodel coupled temperature-displacement driven by the stress/displacement model; Abaqus/Standard analysis.

submodelaxielem_cax4r_gd_xpl.inp: Global DYNAMIC analysis; Abaqus/Explicit analysis.

submodelaxielem_cax4r_sd_std.inp: Submodel DYNAMIC analysis; Abaqus/Standard analysis.

submodel2delem_cps4r_gd_std.inp: Global DYNAMIC analysis; Abaqus/Standard analysis.

submodel2delem_cps4r_sd_xpl.inp: Submodel DYNAMIC analysis; Abaqus/Explicit analysis.

Figures

Acoustic-to-structure submodeling

Elements tested

AC2D4R
AC3D20
AC3D8
AC3D8R
ACAX4R

CAX4R
CPS4R
C3D8R
C3D8
C3D20

S4R
S8R
SAX1

Features tested

The submodeling capability is applied to the coupled acoustic-structural models. The global procedure is performed as a fully coupled acoustic-structural analysis in which the two media are coupled through the use of a tie constraint. Submodeling is performed on the structural component of the global model by using the acoustic pressure from a global acoustic structural model.

Problem description

In the global analysis acoustic pressure acts on either one or both sides of a flat panel. The flat panel is modeled using shell or solid elements. When the pressure acts on both sides of the panel, the correct side from which the acoustic pressures are to be interpolated is specified (see Node-Based Submodeling). The fluid and the structure in the global model have the material properties of water and steel, respectively. The submodel has the material properties of steel. For Abaqus/Standard the direct-integration implicit dynamic and the steady-state dynamic (direct and mode-based) procedures are used in separate tests.

Results and discussion

The loads resulting from the interpolated acoustic pressure from the global analysis are applied correctly on the structure for the single-sided and the double-sided pressure cases.

Input files

Abaqus/Standard Input files

ac2solid_g_c3d20_ac3d20_std.inp: Global analysis using DYNAMIC; fluid on one side; AC3D20 and C3D20 elements.
ac2solid_s_c3d20_ac3d20_std.inp: Submodel analysis using DYNAMIC; submodel driven on one side by acoustic pressure and on the second side by displacements; C3D20 elements.
ac2solid_g_c3d8_ac3d8_std.inp: Global analysis using DYNAMIC; fluid on one side; AC3D8 and C3D8 elements.
ac2solid_s_c3d8_ac3d8_std.inp: Submodel analysis using DYNAMIC; submodel driven on one side by acoustic pressure and on the second side by displacements; C3D8 elements.
ac2solid_g_s4_ac3d8_std.inp: Global analysis using DYNAMIC; fluid on two sides; S4 and AC3D8 elements.
ac2solid_s_s4_ac3d8_std.inp: Submodel analysis using DYNAMIC; submodel driven on both sides by the acoustic pressure; S4 elements.
ac2solid_s_s8r_ac3d8_std.inp: Submodel analysis using DYNAMIC; submodel driven on both sides by the acoustic pressure; S8R elements.
ac2solid_g_c3d8_ac3d8_ssd.inp: Global analysis using STEADY STATE DYNAMICS, DIRECT; fluid on one side; AC3D8 and C3D8 elements.
ac2solid_s_c3d8_ac3d8_ssd.inp: Submodel analysis using STEADY STATE DYNAMICS, DIRECT; submodel driven on one side by acoustic pressure and on the second side by displacements; C3D8 elements.

Abaqus/Explicit Input files

ac2solid_g_c3d8r_ac3d8r_xpl.inp: Global analysis; fluid on one side; AC3D8R and C3D8R elements.

ac2solid_s_c3d8r_ac3d8r_xpl.inp: Submodel analysis; submodel driven on one side by acoustic pressure and on the second side by displacements; C3D8R elements.

ac2solid_g_s4r_ac3d8r_xpl.inp: Global analysis; fluid on two sides; S4R and AC3D8R elements.

ac2solid_s_s4r_ac3d8r_xpl.inp: Submodel analysis; submodel driven on both sides by the acoustic pressure; S4R elements.

ac2solid_g_cax4r_acax4r_xpl.inp: Global analysis; fluid on one side; CAX4R and ACAX4R elements.

ac2solid_s_cax4r_acax4r_xpl.inp: Submodel analysis; submodel driven on one side by acoustic pressure and on the second side by displacements; CAX4R elements.

ac2solid_g_sax1_acax4r_xpl.inp: Global analysis; fluid on two sides; SAX1 and ACAX4R elements.

ac2solid_s_sax1_acax4r_xpl.inp: Submodel analysis; submodel driven on both sides by the acoustic pressure; SAX1 elements.

ac2solid_g_cps4r_ac2d4r_xpl.inp: Global analysis; fluid on one side; CPS4R and AC2D4R elements.

ac2solid_s_cps4r_ac2d4r_xpl.inp: Submodel analysis; submodel driven on one side by acoustic pressure and on the second side by displacements; CPS4R elements.

Intersection-only submodeling

Elements tested

C3D8
C3D8P
C3D8R

Features tested

The submodeling capability is applied using the intersection-only feature, where nodes not found in the global model are ignored rather than labeled as errors.

Problem description

A simple model of a rectangular prism is used. The global model and submodel geometries are identical, but the submodel is shifted in space so that the intersection of the models represents a subset of the submodel geometry. All nodes in the submodel are identified as driven nodes.

Results and discussion

The results show that submodel boundary conditions are applied to driven nodes lying within the global model, while driven nodes lying outside the global model have no submodel boundary condition applied.

Input files

Abaqus/Standard Input files

subm_intonly_g_c3d8_std.inp: Global analysis using C3D8 elements.
subm_intonly_s_c3d8_std.inp: Submodel analysis using C3D8 elements and driven displacements.
subm_intonly_rs_c3d8_std.inp: Submodel restart analysis using C3D8 elements and driven displacements.
subm_intonly_g_c3d8p_std.inp: Global analysis using C3D8P elements.
subm_intonly_s_c3d8p_std.inp: Submodel analysis using C3D8P elements and driven displacements and pore pressures.

Abaqus/Explicit Input files

subm_intonly_g_c3d8r_xpl.inp: Global analysis using C3D8R elements.
subm_intonly_s_c3d8r_xpl.inp: Submodel analysis using C3D8R elements and driven displacements.

Node-based submodeling using field import

Elements tested

C3D6
C3D8
C3D8PH
C3D8R

Features tested

These problems test submodeling for displacement, rotation, pressure, and temperature degrees of freedom.

Problem description

A subset of submodel verification problems in this section are changed to use the field import interface.

Results and discussion

Results are verified by comparison with existing results from submodel verification problems.

Input files

global_fieldimport.inp: Global model using C3D8 elements in a static procedure.
submodel_fieldimport.inp: Submodel using C3D8 elements in a static procedure.
fldimport_gbshell.inp: Global model using S4R elements in a static nonlinear procedure.
fldimport_sbshell.inp: Submodel using S4R elements in a static nonlinear procedure.
gbeam_fieldimport.inp: Global model using CPS4 elements in an implicit dynamic procedure.
sbeam_fieldimport.inp: Submodel using CPS4 elements in a static procedure.
global_c3d6_fieldimport.inp: Global model using C3D6 elements in an implicit dynamic procedure
submodel_c3d6_fieldimport.inp: Submodel using C3D6 elements in an implicit dynamic procedure.
xpl_global_fieldimport.inp: Global model using C3D8R elements in an explicit dynamic procedure.
xpl_submodel_fieldimport.inp: Submodel using C3D8R elements in an explicit dynamic procedure.
xpl_s4_global_fieldimport.inp: Global model using S4 elements in an explicit dynamic procedure.
xpl_s4_submodel_fieldimport.inp: Submodel using S4 elements in an explicit dynamic procedure.

Beam-to-surface submodeling

A beam-to-surface submodel uses beams in the global model and solids in the submodel.

Elements tested

B31
C3D8R

Features tested

These problems test beam-to-surface submodeling for various procedures.

Problem description

The global model is a cantilever beam model that has a channel section. The submodel meshes the same channel section using solid elements.

Results and discussion

The results are verified by comparing the results with the global model solution.

Input files

GlobalBeam.inp: Global beam model with general static step with nonlinear geometry.
GlobalBeamDynamic.inp: Global beam model with the steady-state dynamic procedure.
SubmodelSolid.inp: Solid submodel with the static procedure.
SubmodelSolidDynamic.inp: Solid submodel with the steady-state dynamic procedure.
SubmodelSolidPert.inp: Solid submodel with the static perturbation procedure.
GlobalBeamElset.inp: Global beam model that defines an element set to be used in the submodel.
SubmodelSolidElset.inp: Solid submodel that uses a global element set.