Failure importing section, static mechanical analysis

1

Hello everyone! I am new to the CCX community but so far I love it. I’m currently working on an automated script for simulating mechanical response (simple compression test) of 3D printed lattices. I’ve been able to generate the structures in a separate software and import elements, nodes, BC’s, etc. However, I am consistently receiving the following Error when I import into PrePoMax:

“Error: Failed to import section: *SOLID SECTION, ELSET=ALL_NODES, MATERIAL=MAT_FIG4_TGH_15”

I’m assigning the material to the entire lattice, so the section is simply all elements. I’m using python to modify and compile the .inp file from the secondary software, so I thought it was an issue with my code. However, I tried creating the section from within PrePoMax, then exporting a .inp, then re-importing that same .inp and I receive the same error.

I can attach my .inp input file example if that is helpful. I appreciate any help that could be provided on this!

2

Can you say which software you are using for mesh preparation ? Is it Abaqus ?

3

I’m using nTopology, which is able to output .inp but it needs some slight modifications before using like replacing " " with “_” in certain places

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4

check if you can import it with cgx

5

Ok I’ll give it a shot, here’s a link to .inp if helpful: Lattice_07_20231005.inp - Google Drive

6

It might be better to prepare the geometry in nTopology, export it to STL or STEP and mesh in Gmsh for use in CalculiX.

7

Hi Jpel32 and welcome.
a quick note that caught my attention

ELSET=ALL_NODES

Elset is intended for elements.
¿ALL_NODES, is a set of elements or nodes?

8

nset not according to input deck rules, the manual reads:

First line:
• *NSET
• Enter any needed parameters and their values.
Following line if the GENERATE parameter is omitted:
• List of nodes and/or sets of nodes previously defined to be assigned to this
node set (maximum 16 entries per line).

cgx shows the error when reading.

9

Thank you for looking at my file! Which line do you see “ELEST=ALL_NODES” in ?

10

Hmm that may be the issue. When I was printing the nodesets from python I don’t think I specified 16 per line. I’ll try that and then see what happens, thanks for the advice!

11

It’s right here in your first post:

12

@Calc_em Oh I see. I may have had an older file open when I copied the error message. This is what is reads now:
Error: Failed to import section: *SOLID SECTION, MATERIAL=MAT_FIG4_TGH_15, ELSET=ALL_ELEMENTS
Where ALL_ELEMENTS is just all of the elements.

@JuanP74 I edited my script to output 16 entries max, but am recieving the same error in PrePoMax. Here is the updated .inp file. Lattice_04_20231005.inp - Google Drive

I appreciate everyones help!

13

it works in cgx. I have experienced some issues from prepomax when reading input files. You could try asking in prepomax discourse forum

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14

The inp file importer in PrePoMax still needs some improvements, it doesn’t support all the different forms of mesh definition syntax permitted by CalculiX. It’s a known issue though.

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15

@Jpel32 , It seems like that PrePoMax ver. 1.3.4 and probably also newer versions are capable of loading your structure without errors

Structure
Structure1152×907 247 KB

16

@fgr Interesting, I am using v1.4.1. I will maybe try 1.3.4 and see what happens

17

@fgr @Calc_em @JuanP74 @Disla
I attempted to open the .inp file in v1.4.0 and it worked, seems as though it was an issue with the newer 1.4.1 version. Thank you everyone for your help!

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