Добавил:
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
ANSYS.pdf
Скачиваний:
875
Добавлен:
31.08.2019
Размер:
31.29 Mб
Скачать

vk.com/club152685050 | vk.com/id446425943

Example Submodeling Analysis Input

Figure 9.7: Contour Plots to Compare Results

Figure 9.8: Path Plots to Compare Results

9.3. Example Submodeling Analysis Input

The following example submodeling analysis input listings are available:

9.3.1.Submodeling Analysis Input: No Load-History Dependency

9.3.2.Submodeling Analysis Input: Load-History Dependency

9.3.1. Submodeling Analysis Input: No Load-History Dependency

The following example submodeling input does not include load-history dependency:

!Start with coarse model analysis:

/FILNAME,coarse

! Jobname = coarse

/PREP7

! Enter PREP7

...

 

...

! Generate coarse model

...

 

FINISH

 

Release 15.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information

 

of ANSYS, Inc. and its subsidiaries and affiliates.

253

SAVE
FINISH
RESUME,coarse,db
/POST1
FILE,coarse,rst
SET,...
CBDOF
BFINT,temps,node
FINISH
RESUME
/SOLU
ANTYPE,...
...
/INPUT,submod,cbdo
/INPUT,submod,bfin
DSYMM,...
ACEL,...
...
SOLVE
FINISH
/POST1
...
...
...
FINISH

vk.com/club152685050Submodeling | vk.com/id446425943

/SOLU

! Enter SOLUTION

ANTYPE,...

! Analysis type and analysis options

...

 

D,...

! Loads and load step options

DSYMM,...

 

ACEL,...

 

...

 

SOLVE

! Coarse model solution

 

! Results are on coarse.rst (or rmg, etc.)

SAVE

! Coarse model database file coarse.db

FINISH

 

!Create submodel:

/CLEAR

! Clear the database (or exit program and re-enter)

/FILNAME,submod

! New jobname = submod

/PREP7

! Re-enter PREP7

...

 

...

! Generate submodel

...

 

!Perform cut-boundary interpolation:

NSEL,...

! Select nodes

on

cut boundaries

NWRITE

! Write

those nodes

to

submod.node

ALLSEL

!

Restore full

sets

of

all entities

NWRITE,temps,node

!

Write

all nodes

to temps.node (for

!temperature interpolation)

! Submodel database file submod.db

! Resume coarse model database (coarse.db) ! Enter POST1

! Use coarse model results file ! Read in desired results data

! Reads cut-boundary nodes from submod.node and

!writes D commands to submod.cbdo

! Reads all submodel nodes from temps.node and

!writes BF commands to submod.bfin (for

!temperature interpolation)

! End of interpolation

! Resume submodel database (submod.db) ! Enter SOLUTION

! Analysis type and options

! Cut-boundary DOF specifications

! Interpolated temperature specifications ! Other loads and load step options

! Submodel solution

! Enter POST1

! Verify submodel results

9.3.2. Submodeling Analysis Input: Load-History Dependency

The following example submodeling input includes load-history dependency:

!Start with coarse model analysis:

/FILNAME,coarse

! Jobname = coarse

/PREP7

! Enter PREP7

...

 

...

! Generate coarse model

...

 

FINISH

 

/SOLU

! Enter SOLUTION

ANTYPE,...

! Analysis type and analysis options

...

 

 

Release 15.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information

254

of ANSYS, Inc. and its subsidiaries and affiliates.

! Loads and load step options
! Coarse model solution
! Results are on coarse.rst (or rmg, etc.) ! Coarse model database file coarse.db
! Clear the database (or exit program and re-enter) ! New jobname = submod
! Re-enter PREP7
! Generate submodel

vk.com/club152685050 | vk.com/id446425943

Example Submodeling Analysis Input

D,...

DSYMM,...

ACEL,...

...

SOLVE

SAVE

FINISH

!Create submodel:

/CLEAR

/FILNAME,submod

/PREP7

...

...

...

!Perform cut-boundary interpolation:

NSEL,...

! Select nodes on cut boundaries

NWRITE

! Write those nodes to submod.node

ALLSEL

! Restore full sets of all entities

NWRITE,temps,node

! Write all nodes to temps.node (for

 

!

temperature interpolation)

SAVE

! Submodel database file submod.db

FINISH

 

 

RESUME,coarse,db

! Resume coarse model database (coarse.db)

/POST1

! Enter POST1

FILE,coarse,rst

! Use coarse model results file

SET,...

! Read in desired results data

CBDOF

! Reads cut-boundary nodes from submod.node and

 

!

writes D commands to submod.cbdo

BFINT,temps,node

! Reads all submodel nodes from temps.node and

 

!

writes BF commands to submod.bfin (for

 

!

temperature interpolation)

SET,...

! Read in another desired results data

CBDOF

! Reads cut-boundary nodes from submod.node and

 

!

writes D commands to submod.cbdo

BFINT,temps,node

! Reads all submodel nodes from temps.node and

 

!

writes BF commands to submod.bfin (for

 

!

temperature interpolation)

...

This(SET,CBDOF,BFINT)can be repeated many time

FINISH

! End of interpolation

RESUME

! Resume submodel database (submod.db)

/SOLU

! Enter SOLUTION

ANTYPE,...

! Analysis type and options

...

 

/INPUT,submod,cbdo

! Cut-boundary DOF specifications

/INPUT,submod,bfin

! Interpolated temperature specifications

DSYMM,...

! Other loads and load step options

ACEL,...

 

...

 

TIME

 

SOLVE

! Submodel solution of first steps

/INPUT,submod,cbdo

! Cut-boundary DOF from another set

/INPUT,submod,bfin

! Interpolated temperature from another set

TIME

 

SOLVE

SOLVE as another load step

…..

This (/INPUT..SOLVE) can be repeated many time

FINISH

 

/POST1

! Enter POST1

...

 

...

! Verify submodel results

...

 

FINISH

 

Following is a simple model of a plate with a hole in its middle, with applied displacements in the x direction. To simulate load-history dependency, cut boundary conditions are done at different substeps of the coarse-mesh analysis, then applied as different load steps in the submodeling analysis. The material is assumed to be rate-dependent anisotropic plastic with isotropic hardening.

The problem is solved via the coarse-mesh model, the submodel, and the fine-mesh model, as shown in this figure:

Release 15.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information

 

of ANSYS, Inc. and its subsidiaries and affiliates.

255

vk.com/club152685050Submodeling | vk.com/id446425943

Figure 9.9: Coarse-Mesh Model, Submodel, and Fine-Mesh Model

Both the coarse-mesh model and the fine-mesh model are solved in 20 substeps. The fine-mesh model yields a benchmark solution for comparison purposes.

The submodel analysis is performed in four solutions, as follows:

1.With cut-boundary conditions at only the last substep of the coarse-mesh analysis, solved in one load step with 20 substeps.

2.With cut-boundary conditions at five substeps (that is, at every four substeps) of the coarse-mesh analysis, solved in five load steps each with about four substeps.

3.With cut-boundary conditions at 10 substeps (that is, at every two substeps) of the coarse-mesh analysis, solved in 10 load steps, each with about two substeps.

4.With cut-boundary conditions at all 20 substeps of the coarse-mesh analysis, solved in 20 load steps, each with about two substeps.

The specified load steps and substeps make the size of the substep in submodel solutions close to those in whole-model solutions.

The following figure shows the equivalent plastic strains at point P in each solution:

 

Release 15.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information

256

of ANSYS, Inc. and its subsidiaries and affiliates.

vk.com/club152685050 | vk.com/id446425943

Example Submodeling Analysis Input

Figure 9.10: Equivalent Plastic Strain Through Various Cut-Boundary Conditions and Load Steps

When boundary conditions are cut at more substeps, the results are closer to the fine mesh (the correct solution).

The following figure shows the contour plots of equivalent plastic strain at the end of loading for each of the four solutions:

Release 15.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information

 

of ANSYS, Inc. and its subsidiaries and affiliates.

257

vk.com/club152685050Submodeling | vk.com/id446425943

Figure 9.11: Equivalent Plastic Strain Distributions in a Submodeling Analysis with Load-History Dependency

 

Release 15.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information

258

of ANSYS, Inc. and its subsidiaries and affiliates.