A discrete-continuum coupled finite element modelling approach for fibre reinforced concrete

• Published in: Cement and concrete research 2018-04, Vol.106, p.130-143
• Main Authors: Zhang, H., Huang, Y.J., Yang, Z.J., Xu, S.L., Chen, X.W.
• Format: Article
• Language: English
• Subjects: Angles (geometry); BENDING; Breakage; Cohesive crack model; Computer simulation; Concrete; Cracking (fracturing); Cracks; CRUSHING; DAMAGE; Damage and fracture; Damaged plasticity model; Debonding; DIMENSIONS; ENGINEERING; Failure modes; Fiber pullout; Fiber reinforced concretes; Fiber reinforcement; Fibers; Fibre reinforced concrete; Finite element analysis; FINITE ELEMENT METHOD; Finite element model; Fracture mechanics; FRACTURES; Inclination; Interfacial debonding; Material properties; MATERIALS SCIENCE; Mathematical analysis; Mathematical models; MORTARS; Mortars (material); NONLINEAR PROBLEMS; NOTCHES; PARAMETRIC ANALYSIS; PLASTICITY; Pull out tests; REINFORCED CONCRETE; SCALE MODELS; Spalling; STATIC LOADS; Tensile tests
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/j.cemconres.2018.01.010

Fibre reinforced concrete (FRC) exhibits complicated failure modes such as fibre breakage, mortar cracking, crushing and spalling, fibre-mortar interfacial debonding, depending on many material properties, geometric dimensions, boundary and loading conditions. Most existing numerical models are unable to reproduce these failure modes that may occur simultaneously or sequentially in a specimen, mainly due to difficulties in generating finite element meshes with a large number of randomly-oriented fibres. Herein we develop a discrete-continuum coupled finite element modelling approach for FRC materials capable of effectively simulating all the major failure modes. The continuum damaged plasticity model is used to simulate damage and fracture behaviour of the mortar, while debonding of fibre-mortar interfaces is modelled by nonlinear cohesive interfacial elements. Unique techniques are devised to generate conforming meshes between fibres and the surrounding mortar so that the randomly-oriented fibres are easily modelled. The modelling approach is validated by simulating single fibre pullout tests with different inclination angles, notched and non-notched direct tensile tests and three-point bending beam tests with randomly-distributed multiple fibres. •An easy-to-implement but effective meso-scale modelling approach is developed for FRC.•It is capable of simulating and interpreting all main failure mechanisms in FRC.•It is critically validated by experiments with single or multiple random fibres under various loading conditions.•It can be used to optimise key design factors of FRC at meso/material scale by parametric studies.