LAUSR

Abstract This paper investigates the behavior of 32 high-strength concrete square columns confined by high-strength transverse reinforcement under concentric compression, by applying structural state of stress theory. First, the sum of generalized strain energy density values (Eij) of columns at every load value (Fj) is normalized as Ej,norm to describe the structural state of stress. Then, the Ej,norm-Fj curves reveal the characteristics of the state of stress and failure mechanism of confined concrete columns under load-bearing condition. The Ej,norm-Fj curves also reveal an updated failure load definition and failure criterion. Furthermore, the effects of unconfined concrete compressive strength, volumetric ratio, and transverse reinforcement yield strength on the state of stress are studied. Finally, a formula is proposed to predict the updated failure loads of confined concrete columns. In summary, a novel method to identify some working characteristics of structures is explored.