Quad meshing of a femur 3-D model

Altair Forum User

Hi there,

I am working on a project and my goal is to assign patient-specific bone material properties to a 3-D model created from a set of CT-scans. To do so, I have a segmented 3-D model of the femur resurfaced using solidworks. I have another software called BoneMat that assign the material properties to the bone using the CT-scans as well. But in order to do so, I have to import the bone model as a meshed neutral file (*.ntr). It is my first experience with finite element modelling, and I was wondering if anyone could help in how to mesh my already segmented 3-D model (saved as a .igs that I can import in HyperMesh) and I want to be able to create that (.*ntr) file using this software.

 

Thank you for your help

Altair Forum User

Hi,

 

i don't know the *.ntr format and i don't know if it is supported by Hyperworks.

IGES files you can importing and meshing in any case. But the reference to the right material properties is still a task.

 

Which preference (solver) do you want to use to solve anything and which material do you use inside the preference?

 

Regards,

Mario

Altair Forum User

In that case, do you know how can I output a neutral file using HyperMesh? because when I try to export in ASCII format, it says connectors have not been selected even after I mesh my file!

 

Thank you again for your help

Altair Forum User

With a customized FE output template, you can export the mesh to any (ascii) format.

Altair Forum User

That is exactly what I tried to do and it still shows me the following error message:

 

connectors have not been selected

 

Thank you

Altair Forum User

I could have a look at your model, if you want /emoticons/default_smile.png' alt=':)' srcset='/emoticons/smile@2x.png 2x' width='20' height='20'>

Altair Forum User

http://postimg.org/image/5x4w0lg7n/

 

This is the error message I was telling you about

 

Thanks

Altair Forum User

Hi everyone,

 

I am looking on how to get a Patran Neutral File using Hypermesh. I have the trial version of Hypermesh, could you please confirm that it is not because of a limitation in the version that I cannot find a way to get that neutral file?

Thank you

Altair Forum User

Hi rdam,

I can not found Patran Neutral File in supported format of Hypermesh version 12.0.

Maybe you have to try with another format.

Altair Forum User

Altair Forum User said:

http://postimg.org/image/5x4w0lg7n/

 

This is the error message I was telling you about

 

Thanks

Do you try to export to another format ? It works ?

Altair Forum User

I figured out how to get the Neutral file. Thank you for your help.
 
I have another question,
 
How can I create HEX elements using HyperMesh? I am trying to mesh a femur!
 
Thank you

Altair Forum User

Hi rdam,

 

I have just started working in the FEA area, and I am trying to create a suitable mesh for a lumbar vertebra (L4) and in the end the L4-L5 motion segment (i.e. L4-intervertebral disc - L5).

For this, I have created a 3D cad object from CT data and imported it as an iges file into hypermesh, where I surpressed all edges but one, and used automesh (only trias) to create a new 2D mesh.

However, I want to have different element sizes for different parts due to computational efficiency that have the same element density where they 'meet'  , any ideas on how to achieve this?

 

Also, how do you mesh the difference between cortical and trabecular bone?

 

Thanks in advance!