MODELLING OF CONCRETE USING THE BOUNDARY ELEMENT METHOD AND HOMOGENISATION TECHNIQUE

A 2D boundary element method (BEM) is used to simulate the mechanical behaviour of concrete within a multiscale framework considering the concept of representative volume element (RVE).The problem consists of solving the equilibrium problem in terms of displacement fluctuations at meso-scale of the material.For that, numerical analyses are performed using a consistent tangent operator for BEM formulation.A step-by-step analysis is detailed described for the parametric identification of the variables involved in a uniaxial compression test experimentally tested.The Mohr-Coulomb model is adopted to simulate the mortar matrix while elastic behaviour is considered for aggregates.Besides, the microcracking process at interfacial transition zone is modelled by defining additional cohesive-contact finite elements on interfaces between mortar and aggregates.The proposed numerical model shows its capability to perform this kind of analysis comparing with experimental test.