Design of Ultra-High-Performance Fiber-Reinforced Concrete to Withstand Blast and Impact Loading
Brett Ellis (Georgia Institute of Tech.), David McDowell (Gerogia Tech), Min Zhou ()
Computational Materials Design via Multi-scale Modeling
Wed 1:30 - 2:50
Barus-Holley 190
Although well suited to dynamic loading conditions, Ultra-High-Performance Fiber-Reinforced Concretes (UHPFRCs) have been slow to transition from laboratory testing to structural applications, partly due to a trial-and-error materials development process that is lengthy and expensive. This research seeks to address these problems by implementing a computational materials design framework consisting of blast and impact multi-scale models (MSMs) and the Inductive Design Exploration Method (IDEM) (Choi, H.-J., Ph.D. Dissertation, Georgia Institute of Technology, 2005). At the finest length scale, a 3D model of a single fiber with surface topology is embedded in a matrix to account for plastic work of the fiber, granular flow in the matrix, and sliding friction at the fiber-matrix interface. The resulting pullout force versus end slip relations are projected onto stochastically placed fibers at the intermediate length scale, yielding homogenized traction-separation relations at a crack plane. The invariance of damage initiation stress and dissipated energy density at the crack plane guide the scale transition between intermediate and coarse length scales. At the coarsest length scale, two separate models simulate the response of a finite thickness UHPFRC panel to blast and impact loading. Results from the MSMs are used within IDEM, which is a systematic three-step algorithm that discretizes input variables, projects the discretized set of input variables to a range in the output space, and determines which sets of discrete input values satisfy the output space performance requirements between any two levels of hierarchy. Through recursive applications, IDEM can assist in the design of hierarchical materials by determining ranged sets of input variables that satisfy ranged sets of performance requirements. Results will be presented for the design of UHPFRC materials and panels such that the UHPFRC panels will withstand blast and impact loading.