dear Baharom

in the catia software we can drawing surface and changing it to the solid part by adding thickness , i don't know it's helpful or not! 

Dear Behzad

I just can open the file.model in Catia from Magics. I can not copy & paste the tree from .model to part design or generative surface. I am still stuck. I also try to import the .igs file, it is too many points to join & rebuild as a surface.

A couple of yeas ago, I used RapidForm software to convert the Stl file into an enclosed  surface (surface enclosure with no holes and wrap-arounds). First conveted  STL into Step file,  then imported it into CATIA V5 using CATIA v5 translator and thereafter, performed all post processing (like surface clean-up, etc.) in CATIA v5 to create a full 3D solid model.

I do not have any report on this. But the following paper may be helpful.

Article On Hybrid Structure for Editable PowerCopies

Thank you Brian Prasad @ Slawomir. I will try. Yesterday I use mashlab to convert the stl to DXF & open in Solidworks. file size is about 100MB & my laptop with i7 processor still hang to process it. Will try both tips..haha

Almost every CAD application (SoidWorks, Creo, CATIA, Siemens NX, ..) has a module to deal with imported geometry. STL file format can be easily imported, then you have to close the volume using surfaces and create solid, or you can create solid adding thickness to the imported geometry. Example in CATIA https://grabcad.com/questions/how-to-convert-enclosed-surface-to-solid-in-catia , solidify in Creo, SolidWorks use Knit Surface with Try to form solid option selected.

I hope this will help.

Hi Baharon!! 

Catia can be used to "transform a stl to a solid part". Make the next steps and or follow the next links:

https://www.youtube.com/watch?v=1wtkDL444uw

https://grabcad.com/questions/how-to-convert-enclosed-surface-to-solid-in-catia

1 Open catia Start->Machining->STL Rapid Prototyping

2 A dialog window will appaer. Write a name then ok

3 Look for STL import icon and click it, A dialog window will appear, in "selected file"  browse for your stl file. The click "Apply" then "ok"

4Go to Start->Shape->Quick Surface reconstruction

5 Look for "Automatic surface icon" and click. A dialog window will appear. For "Mesh" select your imported file it is inside the partbody in the part tree. Yo can select diferent mean surface parameters according to your file. Then click "ok" A surface of your file will be created.

6Go to star-> Mechanical design->part design look for close surface icon, click  it. A dialog window will apear, select the surface created in last step in the part tree. A solid of your file will be created as "CloseSurface" in the part tree

I applied this method. at step-5, it give a message (selected mesh contain non manifold vertices). How to fix this issue?