Abstract
The present paper is concerned with fracture mechanism or concrete system in the light of fundamental asppects of fracture mechanics. In the first half, fracture process and fracture mechanism from fracture initiation to ultimate fracture of multi-phase materials were discussed in comparison with fracture of structural system consist of many members, and then the universal properties of fracture criteria of the system subject to multi-axial stresses were discussed on the basis of the structural model of materials. In the second half, fracture mechanism of concrete system was discussed first, then methods of expression of changes of phenomenological response characteristics of the system, which reflect the change of the internal structure of the system, were considered. The structural models of frature of concrete system were also refered.
