R-curve and size effect in quasibrittle fracture: a rewriting of the Bazant's size effect law.

摘要

The recent rewriting of the Bazant's Size Effect Law which has suggested the existence of an additional asymptotic regime for intermediate structure sizes is compared to numerical simulations of fracture of geometrically similar notched structures of different sizes. The quasibrittle failure is simulated through Cohesive Zone Model (bilinear softening) using a constant set of cohesive parameters whatever the specimen size. The different asymptotic regimes expected for the size effect on the nominal strength are shown in fair agreement with the size effect observed on the results obtained from numerical simulations. The existence of the new asymptotic regime expected for intermediate structure sizes is, in particular, clearly revealed by this comparison.