Procedure of statistical size effect prediction for crack initiation problems

Procedure of statistical size effect prediction for crack initiation problems

Paper in proceedings (conference paper)

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 pur-poses – 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 de-terministic nonlinear FEM calculation should follow deterministic-energetic formula, a superim-position with the Weibull size effect, which dominates for large sizes using the energetic-statistical 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.

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 pur-poses – 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 de-terministic nonlinear FEM calculation should follow deterministic-energetic formula, a superim-position with the Weibull size effect, which dominates for large sizes using the energetic-statistical 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.

size effect; quasibrittle materials and structures; extreme value statistics; Weibull statistics; characteristic lengths

Vořechovský, M., Bažant, Z., Novák, D.

14.06.2005

VUT v Brně

Brno

80-214-2853-8

2nd International Symposium NON-TRADITIONAL CEMENT & CONCRETE

433

438

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