Turbomachine blade life assessment with geometric mistuning

This study aims to verify the mathematical models, numerical methods, and software suite developed for assessing the service life of actual turbomachine rotors and confirm their adequacy for industrial applications. The strength analysis of highly loaded turbomachine rotor components, accounting for parameter mistuning, represents a critical challenge in power generation and aerospace engine design. The primary investigative method employed is the finite element method (FEM) in a three-dimensional formulation. The research utilizes theories of elasticity and vibration, mechanics of deformable solids, damage summation methods, and fatigue accumulation hypotheses. The computational framework involves matrix computations, numerical integration, and methods for solving systems of algebraic equations. A durability analysis of a steam turbine wheel model was carried out using TET10 three-dimensional finite elements within the commercial ANSYS WORKBENCH software, enhanced with custom-developed codes. The numerical results from these finite element models for all mistuning types were compared with the experimental data, analytical solutions, and computational results from the ABAQUS software, which incorporated geometric mistuning. This integrated validation confirms the accuracy of the models and facilitates their application not only to simplified steam turbine models but also to real industrial components. The computational experiments verified the proprietary software and the interface that connects it with conventional commercial software for analyzing the service life of a steam turbine with geometric mistuning. The practical significance of this work lies in the applicability of the developed approach for durability assessment in the design and fine-tuning of real axial and radial turbomachinery. This methodology substantially reduces the time and financial costs associated with the development of new compressors and turbines.