Fiber's key characteristics in aligned pullout: insights from computations

Explicitly modeling embedded fibers in a concrete matrix subject to cracking, spalling, and localized crushing presents significant challenges. On top of that, a mesh conforming model of steel fibers embedded in a concrete matrix is computationally expensive. In this study, a hybrid contact model is used to generalize fiber-matrix coupling and remove the necessity of an excessively small mesh. The generalized model simulates the movement of embedded steel bars in a predefined tunnel within a discrete-mesoscopic matrix. There are limited reports on this slideline model, but a universal calibration, parameter fitting, and investigation of geometrical configurations are lacking. To address this and reveal the merits and limitations of the slideline-assisted coupled contact model, cases of steel fiber aligned pullouts are contrasted against the conventional mesh-conforming approach and experimental evidence. Future studies will extend these investigations to include inclined pullout cases, leading to a scalable fiber-lattice explicit coupling model to simulate SFRC composites.