ABSTRACT
This paper presents preliminary numerical simulations of the gap test for plain concrete using an advanced damage-plastic constitutive model. A few fundamental model parameters are calibrated against standard bending tests of geometrically similar specimen sizes of three different sizes. The primary objective is to trace the evolution of the stress and damage distributions during the two loading stages of the full gap test, and to reveal the mechanisms underlying the observed increase and decrease in peak bending load. The results show that the non-uniform, multiaxial stress state and the resulting damage pattern induced during the initial compressive stage critically affect the specimen’s performance in the subsequent bending stage. Such structural effects are suggested to play a more important role than the specific material behavior under tension combined with transversal compression.
