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Why is the loads at the origin of the coordinate system in abaqus?

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1xuanzewuyan

Student
Apr 22, 2022
5
Hello every one:

Rencently,I am working on the finite element analysis of the lumbar spine. I use Hypermesh to mesh model and save it as an inp file, then I use another commercial software to obtain boundary conditions such as constraints, amplitudes, loads, etc., and then I import the two files, but the loads are not distributed around the bones(Pic 1), but at the origin of the coordinate system(Pic 2) and position of constraint is not also correct. I have uploaded file, including grid files and boundary conditions, and I would appreciate it if anyone could help me.

Sincerely.

Pic1
8E6E6326-4697-4083-B77E-E4E72C24948D_yyb0xg.png


238E6E55-D6F7-40DC-A5D0-2B139DAB647B_isl5yd.jpg




Pic 2
8999429A-A0D6-47E8-A4DE-1E369EEA4ED9_t3bxzx.png
 
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Please check if you can download the file using this link - it's not working for me. Maybe because of redundant extensions in the name of the file.

Can you say more about how you obtained these definitions and then exported and imported them ? Which software, file formats and tools did you use for that ?
 
Dear “FEA Way”:

Thank your for you reply. I cant‘t reupload the file, so i am sorry about that. But i believe that you only need to rename the file to “xx.zip” to open the file. Or you can leave your email address and I'll send the model to the mailbox. I'll explain in detail how these two files were obtained later.

Sincerely.
 
The problem is that I can't download the file at all so I don't have a chance to rename it. We can't share e-mails here due to a risk of spam. So you would have to upload the file again in a new reply, it should be possible (unless you don't have access to this file anymore).
 
Dear "FEA Way";

I use the Anybody Modeling System(biomechanics modeling software)to export muscle force, joint reaction force and so on(Pic 1), these data are in xml format. Then this software provide the plug-in, this plug-in can combine the boundary conditions of this xml format with the mesh file, eventually, you will get a output.inp file(Pic 2). The first line of output.inp which contains a reference, that is, the path to the mesh file, and then the rest are all boundary conditions, load, muscle force, amplitude, and so on. Unfortunately, the plug-in is very old or not compatible with abaqus. When I imported output.inp, abaqus popped up a lot of warnings showing The keyword misplaced(Pic 3).... However, when I use hypermesh to mesh and generate an inp file, there is no warning to import abaqus, but the display of loads and constraints becomes abnormal. So, I think I'm in a dilemma.
Do you have any experience dealing with this kind of problem?

Sincerely.

Pic 1
%E5%BE%AE%E4%BF%A1%E5%9B%BE%E7%89%87_20220422170041_cuvdrm.png


Pic 2
%E5%BE%AE%E4%BF%A1%E5%9B%BE%E7%89%87_20220422170145_ezy2bx.png
%E5%BE%AE%E4%BF%A1%E5%9B%BE%E7%89%87_20220422170159_kozmbq.png
%E5%BE%AE%E4%BF%A1%E5%9B%BE%E7%89%87_20220422170153_rpfesk.png


Pic 3
%E5%BE%AE%E4%BF%A1%E5%9B%BE%E7%89%87_20220422170328_ovc70s.jpg
 
However, I have an "unconventional" way of handling warnings, which is to delete all the *part and *Assembly keywords in the mesh file, but I don't think this is the best solution to the problem. I have uploaded mesh and boundary files in the attachment. After the two files are imported into ABAQUS, the loads and constraints are displayed normally.
 
 https://files.engineering.com/getfile.aspx?folder=f1fc719f-d1db-4232-a219-4c3a9de410eb&file=normal.zip
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