Learning Forum

[nils-erik.sanhen]

Hello,

I created a small example to find out how I can use the shell-solid submodelling feature in apdl. Unfortunately I did not manage to write the d constraints in the .cbdo file. 

I followed this related topic: https://innovationspace.ansys.com/knowledge/forums/topic/how-are-the-displacement-constraints-d-commands-in-cbdo-file-related-to-prnsol-displacements-at-the-cutboundary-nodes-if-the-nodes-are-coincident-at-cutboundary-in-the-coarse-and-the-submodel-i/

But I don't know how I have to update my code to generate the constraints, does someone has an idea for me?

Best greetings,

Nils

 

 

import os

import numpy as np

import pandas as pd

 

from ansys.mapdl import core as pymapdl

 

# Start MAPDL as a service

mapdl = pymapdl.launch_mapdl()

# print(mapdl)

### Basic settings

# Creates a jobname for the coarse model

mapdl.filname(fname = 'Shell_global')

# Enter the preprocessor

mapdl.prep7()

# Create a title for the coarse model

mapdl.title(title = 'Shell_global')

# Set analysis type to static

mapdl.antype(antype = 'static')

 

 

### Define variables and materials

# Define material

mapdl.mp(lab = 'ex', mat = 1, c0 = 30E6)

mapdl.mp(lab = 'NUXY', mat = 1, c0 = 0.3)

 

# Define Geometric parameters

l_plane = 3

l_detail = 1

h_detail = 1 # total height

 

 

### Setup model

# Define Keypoints

mapdl.k(npt = 1, x = 0, y = 0)

mapdl.k(npt = 2, x = l_plane, y = 0)

mapdl.k(npt = 3, x = l_plane, y = l_plane)

mapdl.k(npt = 4, x = 0, y = l_plane)

# Define lines

mapdl.l(p1 = 1, p2 = 2)

mapdl.l(p1 = 2, p2 = 3)

mapdl.l(p1 = 3, p2 = 4)

mapdl.l(p1 = 4, p2 = 1)

# Define area

mapdl.al(1,2,3,4)

 

mapdl.lesize(nl1 = 'all', ndiv = 3)

 

mapdl.sectype(secid = 1, type_ = 'SHELL')

mapdl.secdata(h_detail)

mapdl.et(1, "SHELL181", 2)

# Set to quads elements (key = 0)

mapdl.mshape(key = 0, dimension = '2D')

# Specifies whether free meshing or mapped meshing should be used to mesh - mapped meshing (key = 1)

mapdl.mshkey(key = 1)

 

mapdl.amesh('all')

 

 

### Create BC and forces/displacements

# Create fixed conditions

mapdl.nsel("s", "loc", "x", 0, 0)

mapdl.d(node="all", lab="ux", value=0.0)

mapdl.d(node="all", lab="uy", value=0.0)

mapdl.d(node="all", lab="uz", value=0.0)

#Apply displacements (1/20 of the Lenght of the cube)

mapdl.nsel("s", "loc", "x", l_plane, l_plane)

mapdl.d(node="all", lab="ux", value = l_plane * 1/20)

mapdl.allsel()

 

 

 

 

### Run model

mapdl.finish()

mapdl.run("/SOLU")

mapdl.outres("all", "all")  # Save all result items for all nodes

mapdl.solve()

mapdl.finish()

 

 

# Save .db file --> name is as model fname: Cube_global_coarse.db

mapdl.save()

# Go in postprocessing --> should create the .rst file

mapdl.post1()

mapdl.set(1, 'LAST')

 

 

 

 

 

test = mapdl.prnsol('U')

 

print(test)

 

 

 

 

 

mapdl.clear("NOSTART")  # CLEAR THE DATABASE

mapdl.filname("Solid_submodel")  # DEFINE JOBNAME FOR THE SUBMODEL

mapdl.prep7()

# Create a title for the coarse model

mapdl.title(title = 'Solid_submodel')

mapdl.antype(antype = 'static')

 

 

# Define material

mapdl.mp(lab = 'ex', mat = 1, c0 = 30E6)

mapdl.mp(lab = 'NUXY', mat = 1, c0 = 0.3)

 

 

### Setup sub-model

# Define Keypoints

mapdl.k(npt = 10, x = l_detail, y = l_detail, z = 0.5*h_detail)

mapdl.k(npt = 11, x = 2*l_detail, y = l_detail, z = 0.5*h_detail)

mapdl.k(npt = 12, x = 2*l_detail, y = 2*l_detail, z = 0.5*h_detail)

mapdl.k(npt = 13, x = l_detail, y = 2*l_detail, z = 0.5*h_detail)

mapdl.k(npt = 14, x = l_detail, y = l_detail, z = -0.5*h_detail)

mapdl.k(npt = 15, x = 2*l_detail, y = l_detail, z = -0.5*h_detail)

mapdl.k(npt = 16, x = 2*l_detail, y = 2*l_detail, z = -0.5*h_detail)

mapdl.k(npt = 17, x = l_detail, y = 2*l_detail, z = -0.5*h_detail)

# Define volume

mapdl.v(10,11,12,13,14,15,16,17)

 

 

# Define element type

mapdl.et(itype = 1, ename = 'SOLID185')

 

 

 

# Define Mesh size

mapdl.esize(size = 0.25*h_detail)

# performing the meshing

mapdl.vmesh('all')

 

# Select node at cut boundary

mapdl.nsel("s", "loc", "x", l_detail, l_detail)

mapdl.nsel("a", "loc", "x", 2*l_detail, 2*l_detail)

mapdl.nsel("a", "loc", "y", l_detail, l_detail)

mapdl.nsel("a", "loc", "y", 2*l_detail, 2*l_detail)

# WRITE GEOMETRY TO Solid_submodel.node

mapdl.nwrite(fname="Solid_submodel", ext="node") 

 

 

mapdl.allsel()

mapdl.finish()

# SAVE SUBMODEL DATA IN FILE Solid_submodel.db

mapdl.save()

mapdl.post1()

 

 

# Starts complete coarse model again

mapdl.resume("Shell_global", "db")

# Load result files from coarse model

mapdl.file("Shell_global", "rst")

 

mapdl.cbdof(fname1 = 'Solid_submodel', ext1 = 'node', fname2 = 'Solid_submodel', ext2 = 'cbdo', kpos = 0, kshs = 1)

 

 

### From this point on the submodel is investigated

mapdl.prep7()

 

# RESUME SUBMODEL FROM FILE Cube_submodel.db

mapdl.resume("Solid_submodel", "db")

# READ IN INTERPOLATED B.C.'S FROM Cube_submodel.cbdo

# :label — Begins reading from the first line beginning with the matching user-defined label :label

mapdl.input(fname = "Solid_submodel", ext = "cbdo")

mapdl.input(fname = "Solid_submodel", ext = "cbdo", Line = ":cb1")

mapdl.allsel()

 

# Enter the solution process

mapdl.slashsolu()

 

# Solve fine model

mapdl.solve()

mapdl.finish()

 

 

# Postprocessing

mapdl.post1()

mapdl.set(1, 1)

[deepak.deepak]

 

 

Hi,

Please look into these two documents, which might help to build the shell-to-solid submodel.

7.2. Using Submodeling

7.4. Shell-to-Solid Submodels

Thanks,

Deepak

Ansys Help
Ansys Learning Forum (Rules & Guidelines)

 

 

 

[nils-erik.sanhen]

Hello,

thank you for your reply.

In the modelling procedure I followed the manual. And I was able to create a solid-solid submodel. But in the follow up step, to create a shell-solid submodel, I was not able to generate a .CBDO consist out of an NMODIF block and and D block (dexcriped on page 148 of the document). My model consist soly on NMODIF commands. So I try to figure out what the cause of the problem is and how I can fix it.

If you have further ideas or examples I could take a look on, I would be happy.

Best greetings,

Nils Sanhen

[deepak.deepak]

 

Hi, 

Please refer to this example, I was able to generate a .cbdo file, with NMODIF,DDELE, and D blocks.

!SHELL_MAIN_MODEL

/clear

/FILNAME,Mainmodel   

/PREP7



!MATERIAL PROP

MP,EX,1,2E5, ! MPa

MP,NUXY,1,0.3,



! Shell Element

ET,1,181

sectype,1,shell

secdata,4

secoff,mid



!GEOMETRY

K,1,0,0,0   

K,2,0,0,10  

K,3,20,0,10 

K,4,20,0,0  

A,1,2,3,4  



!MESHING

MSHAPE,0,2D 

CM,_Y,AREA  

ASEL, , , ,1 

CM,_Y1,AREA 

CHKMSH,’AREA’   

CMSEL,S,_Y  

AMESH,_Y1 



!SUPPORTS

NSEL,S,LOC,X,0

D,ALL,ALL

ALLSEL,



NSEL,S,LOC,X,20,

F,ALL,FX,1E5

F,ALL,FY,0

F,ALL,FZ,0

ALLSEL

FINISH



/SOL

SOLVE,

FINISH



SAVE



!********************************

!****SHELL_TO_SOLID_SUB_MODEL****

!********************************

/CLEAR

/FILNAME,Submodel   

/PREP7  

ET,1,SOLID185   

MP,EX,1,2E5, ! MPa

MP,NUXY,1,0.3,



!Sub_model GEOMETRY

BLOCK,0,10,-2,2,0,8,



MSHAPE,1,3D 

MSHKEY,0

CM,_Y,VOLU  

VSEL, , , ,1 

CM,_Y1,VOLU 

CHKMSH,’VOLU’   

CMSEL,S,_Y

VSWEEP,_Y1

CMDELE,_Y   

CMDELE,_Y1  

CMDELE,_Y2



!NROTAT

NSEL,S,LOC,X,10

NSEL,A,LOC,Z,8

NROTAT,ALL,

ALLSEL,ALL



!NWRTIE

NSEL,S,LOC,X,10

NSEL,A,LOC,Z,8

NWRITE,

ALLSEL,ALL

FINISH



SAVE



!Resume of Mainmodel



RESUME,Mainmodel,DB

/POST1

FILE,’Mainmodel’,’rst’,’.’  

SET,LAST

CBDOF,’Submodel’,’node’,’ ‘,,,,0, ,1,

FINISH,



!Resume back to Submodel

RESUME,Submodel,DB



/PREP7 ! The .cbdo file must be read in PREP7

/INPUT,,cbdo        ! Reads Jobname.cbdo up to the /EOF command

/INPUT,,cbdo,,:cb1  ! Reads same file from the label :cb1

DCUM,ADD



!SUPPORTS

NSEL,S,LOC,X,0

D,ALL,ALL

ALLSEL,



FINISH



/SOLU

SOLVE

FINISH



/POST1  

SET,LAST

PLNSOL,U,X,0,1.0

Thanks,

Deepak

 

[nils-erik.sanhen]

Thank you very much, for your help!

It's working exactly as it should.

Best,

Nils