This paper, more than any other, has shaped my thinking on my thesis. It combines continuum and truss topology optimization meshes to simulate the behavior of reinforced concrete. While I read it for the first time, all I could think was "how cool would it be to build one of these?"
It was written by Andrew T. Gaynor, James K. Guest, and Christopher D. Moen, with whom my advisor Josephine V. Carstensen worked during her PhD.
The full-length paper can be found here.