The roughness of crack surfaces of heterogeneous quasi-brittle materials such as concrete, bones, rock and wood is linked to the spatial extension of the fracture process zone [1]. Modelling of this zone is required to predict the influence of size on the nominal strength of geometrical similar structures made of quasi-brittle materials or crack spacing in reinforced structures [2].

The aim of this study is to further investigate the link between the heterogeneity of the material and the roughness of crack surface by means of discrete network analyses of the failure process of heterogeneous quasi-brittle materials. In the present study, a 3D periodic unit cell of a irregular structural network representing a heterogeneous material is subjected to direct tension. The material meso-structure is modelled by a random field of the material strength mapped on the irregular network of discrete elements. The influence of the standard deviation of the random fields on the crack roughness is investigated.

REFERENCES

[1] D. Xenos, D. Grégoire, S. Morel and P. Grassl. "Calibration of nonlocal models for tensile fracture in quasi-brittle heterogeneous materials." Journal of the Mechanics and Physics of Solids. Vol. 82, Pages 48-60, 2015.

[2] Z. P. Bažant, Scaling of Structural Strength, Hermes-Penton, 1202.