W.J. BERANEKand G.J. HOBBLEMAN University of Technology, Delft

A new approach for modelling of brittle materials is suggested: (i) the continuum is replaced by a geometrical configuration of solid sph eres with small contact zones between them; (ii) for the contact zones a criterion of failure is defined on a physical basis; (iii) to simplify calculations, the configuration of spheres is replaced by a space grid with rigidly fixed members; (iv) calculations are carried out on a linear elastic basis; (v) the model is treated as a “lattice-model” that is members are either removed or given other properties, after the bond between the spheres is broken. This ideal brittle material has mainly been introduced to give a physical explanation for axial splitting of brink materials under uniaxial compression. In the paper the mechanical properties of the material are determined. They prove to be dependent on the orientation of the grid towards the direction of the external load. The influence of the masonry joints for uniaxial compression can be introduced. Finally the basic properties of the material which should be determined primarily and to what extent these properties can be obtained from standard tests are discussed.