Size effects in brittle specimen with microcrack interaction

A numerical micromechanics model to simulate the failure process of finite sized brittle specimen with random interacting microcracks is proposed in this paper. The model combines the closed form crack solutions with boundary element method. Strength size effect is studied through the computational results from varied specimen sizes with different crack size distributions, from complete randomness to deterministic situations. The results reasonably explain why the size effect prevails in brittle materials containing disordered microimperfections. The more disordered crack size distribution provides lower strength and stronger strength size effect. (C) 1997 Elsevier Science Ltd.