High-energy rotating components of gas turbine engines may contain rare material anomalies that can lead to uncontained engine failures. A zone-based risk assessment approach can be used to estimate component fracture risk based on groupings of finite elements (FEs) called zones. Creating zones manually is time consuming and requires human judgment. Algorithms have been developed to automatically create zones based on individual FEs, but the associated computation times increase exponentially with the number of FEs. 3D FE models typically contain millions of finite elements. Computation of component risk using individual FE-based automated zoning algorithms may take days or even weeks to complete. An improved optimal autozoning methodology has been developed that substantially reduces the computation time associated with fracture risk assessments. It combines finite elements with similar properties (i.e., stress, temperature, proximity to the surface) into groups called “pre-zones”. An automated zone creation algorithm is applied to pre-zones rather than individual FEs, reducing the overall number of computations. In this paper, the optimal autozoning methodology is presented and illustrated for FE geometries in both 2D and 3D gas turbine engine components. Based on the demonstration problem results, it is shown that the computation speed associated with the optimal autozoning algorithm is expected to be three to four orders of magnitude faster than a previous algorithm that created zones at individual FEs. The pre-zoning-based algorithm also requires less memory than previous algorithms, enabling it to solve much larger models. The resulting algorithm provides a feasible and realistic solution for fracture risk assessment of 2D and 3D component finite element models.

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