A dynamic meso-scale model of the pullout behavior for non-straight fibers and corresponding DEM3 simulation

Abstract

Lots of work had been reported in the experimental investigation and modeling of the debonding and pullout behavior for straight crack-bridging fibers in brittle matrix composites, but few of them involving in the dynamic and/or non-straight fiber case. In this paper, a dynamic meso-scale model for non-straight fiber was proposed on the work of Chanvillard. The model was time-dependent and related to the impact loading through the interfacial shearing stress along the embedded part of the steel fiber, and properly setting the thresholds, the dynamic meso-damage model of the fiber's debonding and pullout process was eventually constructed. The model prediction fitted the experimental data of Chanvillard for non-straight steel fiber under static condition quite well and could demonstrate the rate sensitivity of the reinforcing effects of fibers. Then, a 3-D discrete meso-element method (DEM3) was used to simulate the dynamic pullout behavior of such fiber configurations as wiredrawn fibers from cementitious matrix with pores. Comparing to afro-mentioned model, DEM3 was more effective in simulating the complete procedures of matrix dynamic failure and fiber pullout and would be more helpful in the analyses of complicated configurations of fiber.