Procedure of statistical size effect prediction for crack initiation problems

An improved generalized law for combined energetic-probabilistic size effect on the nominal strength for structures failing by crack initiation from a smooth surface is used for practical purposes – the paper proposes a procedure to capture both deterministic and statistical size effects on the nominal strength of quasibrittle structures failing at crack initiation. The advantage of the proposed approach is that the necessity of time consuming statistical simulation is avoided, only deterministic nonlinear fracture mechanics FEM calculation must be performed. Results of deterministic nonlinear FEM calculation should follow deterministic-energetic formula, a superimposition with the Weibull size effect, which dominates for large sizes using the energeticstatistical formula, is possible. As the procedure does not require a numerical simulation of Monte Carlo type and uses only the results obtained by deterministic computation using any commercial FEM code (which can capture satisfactorily deterministic size effect), it can be a simple practical engineering tool.