Multi-scale dynamic fracture model for quasi-brittle materials

The dynamic fracture of quasi-brittle heterogeneous materials is governed by processes at several different scale levels. Each of these processes is either independent or dependent on the others. In order to model the dynamic fracture of such materials, it is necessary to account for all the rupture processes that contribute to the overall fracture process. This paper presents a structural-temporal approach for the analysis of the multi-scale nature of dynamic fracture based on the notion of a spatial–temporal fracture cell for different scale levels. The problem of the experimental determination of fracture parameters at a given scale level and their possible interconnections with higher and lower scale levels are discussed. It is shown that these interconnections can permit the prediction of fracture parameters on a higher (real) scale level based on the test data obtained on a lower (laboratory) scale. This predictive capability is of vital importance in many applications in which it is not possible to evaluate the dynamic material properties on the real structural scale level (e.g. geological formations, large concrete structures, trunk pipelines, etc.).