ENERGY DISSIPATION IN ULTRA-HIGH PERFORMANCE FIBER-REINFORCED CONCRETE (UHPFRC) SUBJECTED TO RAPID LOADING

As part of a hierarchy-based computational materials design effort, a fully dynamic 3D mesoscale model is developed to quantify the modes and effects of energy storage and dissipation in Ultra-High Performance Fiber-Reinforced Concrete (UHPFRC) subjected to rapid loading. This model accounts for three constituent components: reinforcement fibers, cementitious matrix, and fiber-matrix interfaces. Microstructure instantiations encompass a range of fiber volume fraction (1-2%), fiber length (10-15 mm), and interfacial strength (1-100 MPa). Rapid loading occurs through the application of a time-varying pressure. Calculations allow the delineation and characterization of the evolution of kinetic energy, strain energy, work expended on interfacial damage and failure, frictional dissipation along interfaces, and bulk dissipation via granular flow of the matrix as functions of microstructure, loading, and constituent attributes. The computed relations highlight avenues for designing UHPFRCs with properties tailored for specific load environments and reveal trade-offs between various design scenarios.