Introduction

Innovative model for probabilistic fatigue assessment of components in the presence of defects. The model can evaluate various sources of variability and correctly calculate the effect of surface-exposed and internal defects. Computational time is drastically reduced through an implicit description. Based on a FE analysis, the defect distribution and fatigue strength of the material, the model estimates the critical defect size and failure probability.

Technical features

Model for probabilistic fatigue assessment of components in the presence of manufacturing defects. The model considers the distribution of defects evaluating the effect of surface-exposed or embedded flaws and accounts for the major sources of variability without performing heavy Monte Carlo simulations. The implicit formulation allows a significant reduction of computational time and cost with respect to explicit analyses. Improved estimates are obtained by an analytic evaluation of the effect of surface and internal defects. The model allows flexibility in the description of material resistance and defect distribution. The outputs are the failure probability, the critical locations, and the critical defect size in any region of the part.

Possible Applications

• Fatigue assessment of components produced with metallic alloys or homogeneous materials in the presence of manufacturing defects (e.g. caused by Additive Manufacturing, casting, forging);
• Possible applications sectors include among the others aerospace, medical, automotive.

Advantages

• Correct analytic calculation of failure probability for surface-exposed and internal defects;
• Reduced computational time and cost with respect to state-of-the-art explicit fatigue crack growth simulations;
• Fully-probabilistic model;
• High flexibility in data description.