Bone model in solidworks 2

[Jlog50]

Hello all,

I have a solidcomplex bone part in solidworks 2010 and I need to model partion the model, so the first 3mm thickness is one part and the rest in the middle is another part.

The reason I need to do this is so I can define different material properties to each of the two areas in abaqus.

Any advice on this? Thanks

 

[SolidWorksEngineer]

Try Mold Tools - Cavity. I hope thats works.

If not then try some other mold tools. If you give the file, then we can try something.

http://solidworksengineer.com

 

[Eltron]

Try using offset surfaces.

Dan

http://www.eltronresearch.com

Dan's Blog

 

[CorBlimeyLimey]

Use the Shell function to create the cavity.
Create a Zero Offset from the inner surfaces.
Thicken that surface and use the Create solid from enclosed volume option.

 

[CorBlimeyLimey]

A simpler alternative;

Offset the outer surfaces by 3mm.
Use that surface as the cutting tool in the Split function.

 

[Jlog50]

Hello all,

I have uploaded my part file to

http://my.engineering.com/pg/file/OptiEng

called "Pelvis Solidworks".

I can not seem to do any offseting from the outer surfaces. If anyone could take a look to help that would be much appreciated.

Thanks

 

[rstupplebeen]

I downloaded the part but it appears to be empty, 0 bytes.

Rob Stupplebeen

 

[rgrayclamps]

Hi,

Depending surface geometries, offset by 3mm may not exist.

Best regards,

Alex

 

[CorBlimeyLimey]

I agree with Alex ... if any external radius is 3mm or less, a 3mm inward offset will not work.

 

[rstupplebeen]

My guess is that most of the geometry will not have issues. You may need to split surfaces and recreate the problematic areas individually.

Could you try to post your model here?

I hope this helps.

Rob Stupplebeen

 

[Jlog50]

I am having real problems uploading any files at the moment here or at engineering.com. I am not sure why. I will keep trying. Thank-you all for your input.

By the way I checked the minimum radius of curvature on the model and it is 1e-5 mm.

 

[rgrayclamps]

Hi, Jlog50:

Then there is no solution. Topology of the skin surfaces will prevent you from offseting successfully.

What are you trying to do to split the body? I would like to see the bone model.

Best regards,

Alex

 

[Jlog50]

Ok managed to upload the file.

I am also trying to smooth the surfaces if possible in solidworks as I seem to be getting bad tet quality when meshing in abaqus.

Thanks

 

[rstupplebeen]

I got the file. Here is a running list.

1. Import diagnostics turns up 2 bad surfaces that can be repaired.
2. Unable to shell or offset by 3mm most likely due to others comment of minimum radius.
3. Tools check - select only minimum radius multiple surfaces are around ~1e-7
4. Delete face with tangent fill on each minimum curvature surface. I did 6 before stopping this route.

I believe that many of your surfaces will have significant issues with this large offset. I suggest starting with the largest ones and working your way down from there. Once you are satisfied that your geometry is appropriate create tangent fills to stitch together. You may need to trim or extend surfaces to create the internal solid. Good luck.

In Abaqus you are going to have issues with all of these odd sliver and small surfaces. In SolidWorks you can delete multiple surfaces and use a tangent fill. In Abaqus you can use virtual topology to do a similar operation.

I hope this helps.


Rob Stupplebeen

 

[rstupplebeen]

I just tried offsetting the socket by 3mm and got the green surface in the section cut. My guess is that the cortical bone's geometry is much more complex than a 3mm offset.

Rob Stupplebeen

 

[Jlog50]

I have another question.

I am trying is to simplfy the geometry. Is there any feature in solidworks to simplfy the geometry of this part? If not then what would be the best way around simplfy the geometry?

Many Thanks

 

[SnowCrash]

When I've had this issue of complexity in the past I have been able to add radius and fillet features to eliminate sharp corners.
"roundoff errors"

--
Hardie "Crashj" Johnson
SW 2010 SP 4.0
HP Pavillion Elite HPE
W7 Pro, Nvidia Quaddro FX580

 

[rbpmc]

I would make a copy of this complex geometry and apply a scale factor that would equate to the 3mm surface reduction, then use the scaled model as combine subtract tool.How exact does the 3mm need to be?

 

[Jlog50]

Thanks for you suggestion rbpmc, that should be sufficient for what I need. Thanks everyone too!