Solid to Mid Plane surface converter

[meck]

Hi Everyone,

I was just wondering if anyone knew of a program to convert 3D solids to a mid plane surfaces? We need our models in this form to do FEA work on them. I wanted to ask this question before I took on the task of trying to create one myself.

Thanks

Meck

[dano0310]

Hi The problem with this for the program we use is that once you have moved a face that joins another part to its midplane you then need to extend its mate by half the thickness of the material. I have toyed with the idea for a while but instead opted to make a macro that creates individual sketches of the beam axis which can then be assigned element properties in our FEA program. What sort of parts are you analysing? Dan

[meck]

The parts are of various shapes and size. Really no standard sizing at all. Most parts are sheet or plate material. Those parts would need to be converted to a mid-plane surface, then the FEA engineers assign thickness to the surfaces in their software.

I'm currently attempting to develop a program to do this. I maybe out of my mind for trying, but it's been fun so far.

[dano0310]

When I do this manually I generally move one face back onto the midplane then delete the other 5 thus turning it into a surface. That was the way I planned on doing it. We then have to extend any joining plates so that they touch the new surface. The first surface will also have to be split where the extend one now touches so that the two meshes will join together. Most of our stuff is made with channels and rhs. That's why I have put off doing it.

[meck]

I plan on "reading" the part's sketches and features, then building an entirely new part made up of only surfaces. The gaps between parts and also weld areas needs to be surfaced as well.  Sounds like an impossible task I know, but I'm actually pretty far a long in just a week's worth of work.

I'd really be interested in knowing how you progress with yours, so please keep in contact with me.

[meck]

I thought I'd check back with you and let you know how I have been progressing. I have been able to develop the surfaces from the solid's sketches, and even place them into assemblies. Unfortunately I have discovered that you cannot trim surfaces with the API. Without this functionality I cannot see any way to fully develop a program to convert solids to surfaces. It was very disappointing when I learned of this.

Have you been attempting a similar program?

[dano0310]

I haven't had much chance to work on mine at all.  I have been doing some shop drawings for concrete tilt panels for the last few months on a large shopping centre.  I have just about finished my program to minimise the effort to do the drawings.  I have a chaser bin from another client I will be working on today which needs converting to iges surfaces. Because it came out of solid works it is always a hassle but i will probably change my way of thinking as I have been doing a bit with sketches in API which i hadn't really touched previously.  Probably wont get to far on it doing just one job but If I can formulate a plan as to how to go about it, it will be a big start.

The way I am thinking at the moment is that I draw a sketch of the profile on the midplane and then extrude the surface between two planes. 

Will keep you posted.

Dan

[meck]

That is exactly how I did mine. The problem is if a feature is cut by another feature there is no way to trim the surface. For example: A simple rectangular plate that has a hole cut in it by another feature. I can create the mid-plane surface of the rectangle, but since the API dosen't allow for trimming surfaces there is no way to make the hole. You could of course translate the hole to the initial sketch, but my models are to complicated to do that. They have revoled cuts on curved surfaces.

[dano0310 · Accepted solution]

Hey Meck
Just wondering if this has progressed any further? We have just bought a license of Ansys with the inventor add-in and designmodeler. Designmodeler actually does everything we required for converting our models to plates. It has an automatic midplane tool which seeks out parallel faces and does the conersion in one hit. You can then use the surface extension tool to extend all the wedges in your model.
The only thing I found painful was deleting fillet faces so I wrote a Vba script to delete and heal the faces before importing into design modeler. Cuts out so much work. A four hour job mistakes an hour.
The best part is that I don't need extensive changes to be done in inventor.

[meck]

Cool. I'll have to check it out when I get the time.

I haven't worked at all on my program since my last post. I have many projects I'm involved with so I haven't had much time.

Keep me posted on any issues or comments you have on Ansys.

Great to hear from you again.