simplifying imported solids for analysis in Cosmosworks

I have an assembly with about 40 parts, many of which are fully detailed.

I need to simplify the geometry before I mesh -- otherwise I get meshing errors and run into memory limits on the PC.

Is there a way to quickly de-feature parts in Solidworks prior to running Cosmoswork? I tried reducing the mesh size but then errors are generated -- the program wants to reduce the mesh size to accommodate all the tiny features. I can determine which features can be kept or not, in terms of the response of the structure.

In Pro/E there is a "shrinkwrap" feature which allows one to defeature parts in one command -- it uses a sliding scale to determine the amount of detailing to simply "remove". The part comes out looking less detailed but retaining its basic topology. Quite useful.

The analysis is a drop test scenario.

Thanks in advance.

Reply to
Mike Pinch
Loading thread data ...

Save the assy as an STL file, this will make it much smaller and anyway, a mesh is only an FEA version of a CAD STL format. This assumes Cosmosworks will import an STL of course.

---------------------------------------------- Posted with NewsLeecher v1.0 Final * Binary Usenet Leeching Made Easy *

formatting link

Reply to
Phil Evans

snipped-for-privacy@tagaerospace.com (Phil Evans) wrote in news:sN- dndumAe5x1QzbnZ2dnUVZ snipped-for-privacy@giganews.com:

An .stl file contains only a model composed of faceted surfaces. An FEA mesh also divides the internal volume.

To address the OP: there is no easy way in SW to defeature a model that I am aware of. However I have not done a lot of analysis work, so someone else may know some tricks. My first thought is to create a derived configuration for each component in which you manually suppress small fillets and any other features not relevant to the anlaysis.

Reply to
Dale Dunn

You are quite correct but most FEA programs would mesh the internals of an STL file because they can import and work with surfaces.

I am not sure about Cosmosworks handling an STL surface as it is run within Solidworks which itself will make a solid out of the imported STL. I dont know if an imported STL solid is smaller than the original it was made from but it will definately be simpler.

---------------------------------------------- Posted with NewsLeecher v1.0 Final * Binary Usenet Leeching Made Easy *

formatting link

Reply to
Phil Evans

snipped-for-privacy@tagaerospace.com (Phil Evans) wrote in news:x_Kdnf3MZ9X6ygzbnZ2dnUVZ snipped-for-privacy@giganews.com:

Sorry, I assumed you had concluded that the faceted appearance of the .stl model was similar to the FEA mesh.

It would be an interesting experiment to see if the imported .stl model meshed more easily or more efficiently than the native model.

I'm skeptical though. stl seems to add faces to the model, which I think will increase the total number of mesh elements. My thinking is that the edge of each face will be a boundary that the mesher won't be able to ignore.

Reply to
Dale Dunn

Just tried creating a simple Solidworks model and then also saving it as an STL. The STL file was 150% bigger than the original. I then imported the STL back into Solidworks as a solid and resaved as a Solidworks native file. The saved file was 10 times as big as the original simple Solidworks file I originally created.

Another theory blown out of the water!!

---------------------------------------------- Posted with NewsLeecher v1.0 Final * Binary Usenet Leeching Made Easy *

formatting link

Reply to
Phil Evans

SW Office Professional has a command named "Simplify". Supposedly, it allows the simplification of SW features, parts and assembly models. The description went on to describe it being used to simplify models for use with Cosmos Express. I would be interested to know if this works! I just happened to stumble across this last night in SW help.

Kman

Reply to
euchre45887

Dear Mike,

Try saving your assembly file as part file and select the option exterior faces. This is similar to what we call as shrink wrap. It will make your assy file as part file with surfaces. You might have to do some cleanup before proceeding for FEA.

here is a screen shot for your reference

formatting link
Regards

Deepak

Reply to
Engineer

This is OK if you are looking for displacements. If you are looking for stresses the STL conversion may introduce ficticious stresses.

TOP

Reply to
TOP

The "simplify" command in SW Utilities works very well - IF you have a native SolidWorks part with features that can be suppressed. It won't work on imported models unless you use FeatureWorks to convert the model into a feature-based model.

"Shrink wrap" or the SolidWorks-equiv, won't help in this case, either. You need to simplify the *geometry* in order to reduce the complexity of the mesh. Converting a part or assembly into a single b- rep with no features won't simplify the geometry.

There are basically three potential approaches:

1) Use FeatureWorks and then remove unnecessary features.

2) Use "direct editing" features to manually simplify the geometry.

3) Use adaptive meshing capabilities to optimize the mesh as much as possible.

A fourth option would be to upgrade to 64-bit Windows and add more memory to your computer. You'd have a huge file that would run slow, but at least it would run.

Reply to
jimsym

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.