Predicting the effect of non-uniform fiber distribution on the tensile response of ultra-high-performance fiber reinforced concrete by magnetic inductance-based finite element analysis

Abstract

on-uniform fiber distribution can significantly reduce the extension of multiple-cracking and favor crack localizations in Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) members under tension with important implication on the sought durability. This work aims at fostering the coupling between a novel Non-Destructive Technique, namely Magnetic Inductance Method (MIM), and Finite Element Method (FEM) to predict the effect of nonuniform fiber distribution on the micro-cracking response of UHPFRC samples under tensile loading.First, uniaxial tensile tests on 5 dumbbell samples of UHPFRC with 3.8% of steel fibers showed that tensile ductility is much affected by the degree of uniformity of the fiber distribution. Thus, FEM analysis was performed with the Concrete Damaged Plasticity model (CDP) in Abaqus software, where the UHPFRC tensile law was scaled by a field variable based on the fiber orientation factor and the fiber efficiency factor (μ0 and μ1) measured by Magnetic Inductance Method (MIM). The field variable scales the UHPFRC tensile law between an upper and a lower bound of the tensile law estimated by a fiber pull-out model and a cohesive law for concrete matrix, respectively. The accuracy of the proposed MIM-FEM method was verified against the experimental results by considering the load-displacement curve, the asymmetric displacement, the crack pattern, the fracture energy, and the evolution of the microcrack opening. Based on the presented results, the proposed MIM-FEM method can map and quantitatively analyze the effect of non-uniform fiber distribution for UHPFRC members under tension, thus providing potential application value for infrastructures, pre-casting and architectural applications more broadly.