Simulation of Deformation Capacity in Reinforced High-Performance Fiber-Reinforced Cementitious Composite Flexural Members

Strategies used to simulate the response of ductile cementitious materials, such as high-performance fiber-reinforced cementitious composites (HPFRCCs), have primarily focused on simulating the ductile cementitious composite material-level response in tension, compression, and shear. However, recent experimental research has shown that the interaction between steel reinforcement and HPFRCCs is critical to the structural performance and deformation capacity of reinforced HPFRCC members. In this paper, an emphasis is placed on predicting reinforced HPFRCC component deformation capacity by studying the reinforcement strain causing fracture in monotonic and cyclic simulations with different reinforcement ratios. All simulations are compared with experimental results from testing of reinforced engineered cementitious composite (ECC) flexural members. A cyclic bond-slip interface material model for reinforced ECC components is developed from experimental data and implemented in a finite-element framework. Numerical simulations of reinforced ECC structural components modeled with perfect bond were compared with the proposed interface bond-slip material model. The results show that including bond-slip behavior in simulations improves predictions of component strength, stiffness, and deformation capacity when the simulations are compared to perfect bond models and experimental results. The sensitivity of simulations to tensile strength and fracture energy is explored, and recommendations for using a damaged fracture energy parameter based on cyclic uniaxial material experiments are discussed. Considerations for understanding factors influencing predicted fracture in reinforced HPFRCC structural components is presented by analyzing reinforcement strain, including bond-slip interface elements, and by using a cyclic fracture energy material parameter.