Dynamic approach for optimal inspection planning of fatigue cracked components

• A new approach is proposed to predict the inspection time for FCG.
• The inspection time optimization for FCG based on previous inspection results
• Validation of the proposed approach on complex engineering parts
• Proposed approach leads to better predict the lifespan of FCG engineering structures.

The Fatigue Crack Growth (FCG) is one of the main processes that can lead to unexpected failure of mechanical components. To ensure appropriate operation of mechanical systems, an inspection maintenance scheduling is required. The goal of this paper is to establish a predictive model for the optimal inspection time based on reliability analysis. The combination of response surface method with the first order reliability method is used to assess the reliability with respect to uncertainties related to geometrical parameters, materials and loading. The proposed approach takes into account the results of previous inspections, where the reliability is reevaluated in this case by using Bayesian approach. The main feature of the proposed model lies in the dynamic consideration of inspection results. A formulation of the total cost function is determined according to the maintenance strategy to be performed; the optimal inspection time is calculated by minimization procedure. A generalization of this method is performed in the case of multiple inspections. In order to validate the proposed method, three applications are discussed in this paper, where the results show the interest of considering dynamic planning of crack inspections.