Multiscale elastoplastic deformation and structural optimization of thin-walled superalloy rings

W-shaped metallic sealing rings serve as critical thin-walled elastic components in modern aero-engines. With a typical wall thickness of only 0.3 mm, these components are highly susceptible to complex localized plastic deformation under cyclic service loads. This localized deformation directly compromises their fatigue life and structural integrity. To address the challenge of predicting performance in such ultra-thin sections, this study establishes a multiscale computational framework. This approach integrates macroscopic Finite Element analysis with Crystal Plasticity Finite Element modeling to explicitly incorporate the real microstructural features and surface topography of the manufactured component. The influence of key geometric parameters, specifically wall thickness and trough radius, on the equivalent plastic strain and local stored energy density was systematically investigated under complex service conditions. The results reveal a critical stiffness-damage trade-off mechanism. Although increasing the wall thickness enhances the macroscopic structural stiffness, it unexpectedly increases the strain localization at the contact interface and accelerates micro-damage accumulation. Conversely, optimizing the trough radius effectively mitigates stress concentrations. These findings provide valuable theoretical guidance for the reliable design of high-performance thin-walled structures by balancing macroscopic rigidity with microscopic plasticity control.