Micromechanical Analysis of Fracture of Concrete

In this paper, a recently developed lattice model for simulating the fracture of concrete is presented. The material is modelled as a lattice of brittle-breaking beam ele ments. The heterogeneity of the material is introduced in three manners: (1) by assigning random strength values to the beams in a regular lattice, (2) by generating a random parti cle structure of the material and assigning different strength values to the beam elements appearing in the various composite materials, and (3) by assigning constant strength values to beam elements in a random lattice. The fracture law is extremely simple, and upon exceedence of the strength of a beam element, it is simply removed from the mesh. The analysis is completely linear elastic. With the model crack face bridging in tension, curvi linear crack growth and the fracture mechanism of double-edge notched four-point-shear beams can be simulated realistically. The model seems very attractive because only a small number of single valued parameters is needed. These parameters can be tuned to experimental data in a relatively simple manner. It is important that the crack shapes found in real materials can be simulated to a high degree of accuracy.