Fracture simulation in quasi-brittle materials: continuum vs micromechanics approach

The crack formation and propagation in quasi-brittle materials are analysed using both a discontinuous-like FE approach (a new simple stress-based displacement discontinuity is introduced by an appropriate stress field correction) and a lattice model (by using a regular triangular lattice model formed by pin-joined truss elements which are assumed to have a linear elastic behaviour in compression and, up to a certain peak load, in tension). Some experimental results related to concrete specimens under tensile monotonic loading are examined and simulated by using both the discontinuous-like FE approach and the lattice model. The simulation results are compared and discussed in order to assess the main features, drawbacks and advantages of such two approaches.