A framework for phase-field modeling of interfacial debonding and frictional slipping in heterogeneous composites

Abstract

Modeling and simulating interfacial shear load transfer in fiber-reinforced composites is crucial for characterizing fiber pullout behaviors. Addressing this complicated topic, this work presents a novel phase-field framework to simulate interfacial failure behaviors in fiber-reinforced cementitious composites. Specifically, a comprehensive constitutive model is proposed to describe both interfacial debonding and frictional slipping, which accounts for snubbing and bonding effects in fiber-reinforced composites. The developed model has the following novel features: (1) The model can simultaneously characterize interfacial debonding and frictional slipping, and thus thoroughly describe the fiber-reinforcing mechanisms in quasi-brittle solids; (2) An interfacial slipping degradation theory is implemented in the model to describe interfacial slippage and stress degradation during slipping; and (3) The model effectively and precisely incorporates the friction law with interface normal vectors. The developed model is successfully validated against experimental and simulated results. Finally, a series of parameter studies are undertaken to provide strategic insights to improve the mechanical properties of the composites. The proposed method adds efficiency and robustness to the study of features and fracture mechanisms of fiber reinforcements in complex fiber–cement systems.