3 unconnected bodies

1

Hello
Hope you are all well
I have a geometry with 3 leaflets that are not connected to each other.
image

I have assigned a fix to the edges of these however, the case does not run. it hangs at:

STEP 1

Dynamic analysis was selected

Newton-Raphson iterative procedure is active

Exit code: 0

And with coupling:
I am coupling this with a fluid (FSI) using PreCICE( preCICE - The Coupling Library | preCICE - The Coupling Library) however, the case does not even run just on its own so I am pretty sure the issue is on the solid side.

./run.sh: line 6: 65708 Segmentation fault (core dumped) ccx_preCICE -i flap -precice-participant Solid

2

Are those heart valves ?

Can you run it from .inp file using standalone CalculiX ? What are the errors then ? And what features are used in this structural model ?

3

I tried running it stand alone and it gives me this and does not run:

Newton-Raphson iterative procedure is active

Exit code: 0

Features:

*DYNAMIC, ALPHA=0.0, DIRECT
0.0001, 1
*BOUNDARY
Nfix, 1, 3
*CLOAD
Ninterface, 1, 0.0

4

How many nodes and elements does this mesh have ?

5

nodes: 743856
elements: 403211
one-dimensional elements: 0
two-dimensional elements: 0
integration points per element: 15
degrees of freedom per node: 3
layers per element: 1

distributed facial loads: 0
distributed volumetric loads: 0
concentrated loads: 1533336
single point constraints: 295113
multiple point constraints: 1
terms in all multiple point constraints: 1
tie constraints: 0
dependent nodes tied by cyclic constraints: 0
dependent nodes in pre-tension constraints: 0

sets: 5
terms in all sets: 2182467

materials: 1
constants per material and temperature: 2
temperature points per material: 1
plastic data points per material: 0

orientations: 0
amplitudes: 2
data points in all amplitudes: 2
print requests: 0
transformations: 0
property cards: 0

6

That’s quite a lot. Are those second-order tetrahedrons ? Can’t you use shells ? Did you try with Pardiso ?

7

Is it really necessary for your simulation to have such a fine mesh on all the edges?
Are you using tets or tris?

1 Like
8

Not necessary. I should be good as long as the shape of the geometry is retained however, I tried applying mesh refinements (in PrePoMax) to reduce this and it still gives me the same mesh.

Do you have any suggestions on how I could reduce the number of cells on the edges whihc come as a default from PPM?

9

I cannot use shell since it is a more complex geometry and is likely to deform a lot after FSI.
I have not tried Pardiso.
Element type is C3D10 for all

10

can you share the geometry?

11

Can I please email it to you directly?

12

norbert@maschinenbauer.at

1 Like