Converting soild to polygon mesh

I created a 3d solid of a bridge with several elements using extrude
command. This model will be used as a geometrical representation of its
structural behaviour. However, I realized that the structural program
only accept polygon mesh. Can I use some command in AUTOCAD to convert
solids to polygon meshs?

Thank you

 

Just a suggestion, try unite as many Solids into one , then export or
import to 3D MAX,
then save the 3D Max drawing in DWG format, all Solids then is made
into polygon meshes.

 

Nice trick.

 

Michael you are the greatest expert here so thanks for the credit.

But also It is the same trick you can use if you have a mesh structure
in AutoCAD and want to "drill a hole" thru it ; the trick is to import
the mesh entity into MAX and then tread it as any Solid ; subtract a
cylinder if you want to "drill a hole". This can be done in 3Ds as mesh
entities are treaded as Solids in 3Ds and MAX and when done, then when
you save it as DWG, and open the drawing again in AutoCAD , --- then
there are the perfect hole in the mesh entity.

 

I never took you for a liar before... ; )