Dynamical Behaviour and Strength of Structural Elements with Regeneration Induced Imperfections and Residual Stresses

Abstract

AbstractRepair techniques allow to refurbish blades of jet engines and extend the service life of engine components. However, the mechanical properties of the repaired blades commonly differ from those of the nominal blades. The changes in vibration behaviour and stress distribution resulting from the repair processes could significantly impair the structural integrity of blades. This work addresses this evaluation of repair-specific influences on the structural integrity of blades of blade-integrated disks (blisks). Numerical methods are employed to model and analyse the structural changes of different repair designs. Using Finite Element (FE) simulations, the influences of different repair techniques and designs are systematically evaluated and compared. To further improve the maintenance procedures of blisks, a computational scheme is developed, which features the optimization of repair designs according to the inspected damage of the blade. Since the corresponding optimization tasks involve multiple conflicting objectives, multi-objective optimization is carried out to identify Pareto-optimal repair designs.