Investigation of mixed-mode fracture of UHPC using a hybrid digital image correlation and peridynamics approach

Abstract

Fracture of ultrahigh-performance concrete (UHPC) is a complicated process. It is difficult to simulate the whole process of crack initiation and crack propagation only using computational mechanics methods. The rapid advances of measurement technique in experimental mechanics make it feasible to set up a synergy between computational mechanics and experimental mechanics to explore the cracking mechanism of UHPC. Based on peridynamics (PD) and digital image correlation (DIC) technique, a hybrid experimental and computational method is proposed to investigate the damage and fracture characteristics of UHPC. Three-point bending tests of UHPC notched-beams were performed and the full-field displacements of the UHPC specimens were measured using DIC technique. The discrete PD model was reconstructed on the basis of the measured data. The damage process of UHPC specimens was simulated by combining the DIC displacement data and the PD model. The simulation results were compared with the experimental observations. The crack propagation paths of the simulation results match well with the experimental observations before the appearance of macro cracks. The results show that the proposed model possesses high accuracy in detecting damage and simulating crack propagation of mode I and mixed-mode fractures.