Not sure what you mean by "without concrete", but I have not seen a beam with inclined and vertical stirrups. Usually its one or the other.

MC: Older designs (or new designs in parts of the world where labor is cheaper than material) use more complex stirrup arrangements or cranked longitudinal bars.

Kiangan: I'm not sure what your "minimum area" is referring to -- do you mean designing an efficient truss of rebar (that will never see concrete)?

Or do you mean using a truss analogy method to size the rebar for an eventual reinforced concrete structure?

If the former, you'll have to put a lot of consideration into the connections between rebar. I have analyzed rebar cages for temporary situations prior to pouring concrete, and there are definitely some basic assumptions that you'll want to revisit -- if that is the direction you're heading, let us know and we can elaborate.

Thanks Lomarandil,
I think your right to your former statement,"designing an efficient truss of rebar" ( without pouring concrete).

What i mean to the "minimum area of rebars" is number of rebars that can stand either compression or tension if loaded.

OK. What are you planning to use for connections?

And what is the intended application? Is this an artwork installation? an industrial structure?