Energetic-Statistical Size Effect in Quasibrittle Failure at Crack Initiation

摘要

The size effect on the nominal strength of quasibrittle structures fail- ing at crack initiation, and particularly on the modulus of rupture of plain concrete beams, is analyzed. First, an improved deterministic formula is derived from the energy release due to a boundary layer of cracking (initiating fracture process zone) whose thickness is not neg- ligble compared to beam depth. To fit the test data, a rapidly con- verging iterative nonlinear optimization algorithm is developed.