The dependence of the fractal dimension of crack on material for brittle fracture in two dimensions

Two-dimension spring square network model involving the nearest and second neighbour bonds is studied by numerical simulation with Gauss-Seidel iteration for brittle fracture Mode I. The material-dependent parameter, G0/G, is introduced in this simulation, G and G0 are the parameters related to the elastic moduli of the nearest and second neighbour bonds, respectively. Brittle fracture of materials with different G0/G are simulated under the same quenched disorder. The fractal dimension of crack fluctuates with G0/G. It seems that it is impossible for different materials to have a universal fractal dimension of crack in brittle fracture. However, it is possible to have different so-called universal fractal dimensions