"Klöppel-Yamada yield condition"

In 1958, when a 28-year-old recipient of a grant from the German Academic Exchange Service (DAAD) at the Institute for Structural Steel of the TH Darmstadt (under Prof. Kurt Klöppel), Minoru Yamada published together with Kurt Klöppel in the journal "Der Stahlbau" (now "Stahlbau"), the essay: Yield polyhedron of the rectangular and I-section under the effect of bending moment, normal and lateral force.

The yield conditions formulated in the article represents a fundamental contribution to generalizing limit load design and went down in the literature as the "Klöppel-Yamada yield condition".