Multi-scale based fracture and damage analysis of steel fiber reinforced concrete

By adding steel fibers into concrete matrix, the strength and toughness of concrete could be well improved especially for high strength concrete. However, despite numbers of recent works to find out the overall mechanical behaviors of high strength fiber reinforced concrete (FRC), the quantitative assessments of load distribution between reinforcement and matrix and fiber bridging for opening cracks are lacking. Thus the present work concentrates on the high strength fiber reinforced concrete in the view of multi-scale analysis. A refined numerical model is developed to simulate the behavior of fiber reinforced concrete in meso-level. The steel fibers are modeled by a large number of truss elements which are randomly distributed within the concrete matrix. The concrete are modeled by 3-D solid element. Based on the stress and strain distributions simulated in the meso-level, the homogenized stress and strain in continuum level are resolved by micro-mechanics. And the homogenized damage evolution curve, which is required for the continuum damage model based structural nonlinear analysis, could be calculated based on the multi-scale damage model. The proposed method offers a hierarchical multi-scale framework to investigate the nonlinear behavior of FRC structure in a considerate way. (C) 2013 Elsevier Ltd. All rights reserved.