rupika
Civil/Environmental
- Apr 3, 2010
- 41
Hi,
I am writing relating to following thread. I tried to follow this method. But I have a problem with UM. (UM -> List -> Other -> Superelement Data) I can't find UM. Please help me.
kenwo (Civil/Environme)
20 Feb 03 6:26
from
2. How can I get the complete stiffness matrix of an element out of ANSYS?
You can list all components of the global stiffness matrix in ANSYS by converting your model into a "super element". To do this:
1. Build your model normally. You do not need to apply any boundary conditions.
2. In the solution processor choose the Analysis Type to be substructuring (Solu -> New Analysis -> Substructuring).
3. Select Solu -> Analysis Options and give your substructure a name (defaults to the jobname) and select the Matrix to be generated to be the Stiffness Matrix. Click OK.
4. Next you need to define the master DOF. Master DOFs are all DOFs that will be considered when assembling the global stiffness matrix. Since you want all components of the matrix just define all DOFs to be master DOF: Solu -> Master DOFs -> Define -> Pick All -> All DOF -> OK.
4. Solve the Problem: Solu -> Solve LS. ANSYS will compute the solution and write the global stiffness matrix into a new file called "name.sub" (name being whatever name you defined in step 3). Do not delete this file. You will need it to later if you want to relist the global stiffness matrix.
5. Click: UM -> List -> Other -> Superelement Data. Set name to the name of your *.sub file, the name you defined in step 3, and set KOPT = Full Contents, then click OK.
6. ANSYS will list all the superelement data. The beginning is just a bunch of header information you do not have to worry about. Scroll down to: GLOBAL DOF SET NODES, LABELS = . Next ANSYS lists the order of the DOF vector for your global stiffness matrix. For example:
GLOBAL DOF SET NODES, LABELS =
1 UX 1 UY 2 UX 2 UY 3 UX
3 UY 4 UX 4 UY
This means that in the subsequent matrix the 1st row and 1st column are associated with the DOF UX at node 1, 2nd is UY1, 3rd UX2, etc. Then follows the listing of the stiffness matrix, e.g.:
ROW 1 MATRIX 1
103846.15 37500.000 -63461.538 -2884.6154 -51923.077
-37500.000 11538.462 2884.6154
ROW 2 MATRIX 1
37500.000 103846.15 2884.6154 11538.462 -37500.000
-51923.077 -2884.6154 -63461.538
etc.
Here, ROW 1 lists the elements of the first row of the stiffness matrix, i.e., K11=103846.15, K12=37500.00, K13=-62461.538, etc.
I am writing relating to following thread. I tried to follow this method. But I have a problem with UM. (UM -> List -> Other -> Superelement Data) I can't find UM. Please help me.
kenwo (Civil/Environme)
20 Feb 03 6:26
from
2. How can I get the complete stiffness matrix of an element out of ANSYS?
You can list all components of the global stiffness matrix in ANSYS by converting your model into a "super element". To do this:
1. Build your model normally. You do not need to apply any boundary conditions.
2. In the solution processor choose the Analysis Type to be substructuring (Solu -> New Analysis -> Substructuring).
3. Select Solu -> Analysis Options and give your substructure a name (defaults to the jobname) and select the Matrix to be generated to be the Stiffness Matrix. Click OK.
4. Next you need to define the master DOF. Master DOFs are all DOFs that will be considered when assembling the global stiffness matrix. Since you want all components of the matrix just define all DOFs to be master DOF: Solu -> Master DOFs -> Define -> Pick All -> All DOF -> OK.
4. Solve the Problem: Solu -> Solve LS. ANSYS will compute the solution and write the global stiffness matrix into a new file called "name.sub" (name being whatever name you defined in step 3). Do not delete this file. You will need it to later if you want to relist the global stiffness matrix.
5. Click: UM -> List -> Other -> Superelement Data. Set name to the name of your *.sub file, the name you defined in step 3, and set KOPT = Full Contents, then click OK.
6. ANSYS will list all the superelement data. The beginning is just a bunch of header information you do not have to worry about. Scroll down to: GLOBAL DOF SET NODES, LABELS = . Next ANSYS lists the order of the DOF vector for your global stiffness matrix. For example:
GLOBAL DOF SET NODES, LABELS =
1 UX 1 UY 2 UX 2 UY 3 UX
3 UY 4 UX 4 UY
This means that in the subsequent matrix the 1st row and 1st column are associated with the DOF UX at node 1, 2nd is UY1, 3rd UX2, etc. Then follows the listing of the stiffness matrix, e.g.:
ROW 1 MATRIX 1
103846.15 37500.000 -63461.538 -2884.6154 -51923.077
-37500.000 11538.462 2884.6154
ROW 2 MATRIX 1
37500.000 103846.15 2884.6154 11538.462 -37500.000
-51923.077 -2884.6154 -63461.538
etc.
Here, ROW 1 lists the elements of the first row of the stiffness matrix, i.e., K11=103846.15, K12=37500.00, K13=-62461.538, etc.