ISBN 9783843958028

978-3-8439-5802-8, Reihe Luftfahrt

Hendrik Dominik Linder
Enabling topography-resolving contact simulations in structural dynamics: Developing a coupled FE-BE multi-scale method to resolve macro- and meso-contact scales

143 Seiten, Dissertation Universität Stuttgart (2026), Softcover, A5

Zusammenfassung / Abstract

Modern turbomachinery components are designed as lightweight structures, making them prone to high-cycle fatigue. Since material damping is typically negligible, structural integrity is largely governed by energy dissipation through dry friction at mechanical joints. Precise contact modeling is therefore indispensable, yet challenging due to its multi-scale nature: real joint surfaces are neither smooth nor flat but exhibit macro-scale form deviations, meso-scale waviness, and micro-scale roughness, all of which can affect system damping. Research over the past decade indicates that topography-resolved contact simulations based on Coulomb–Signorini laws can capture these topography-dependent effects on system damping. However, standard full-FE simulations cannot realize this modeling strategy.

This thesis develops a coupled FE-BE multi-scale method (MSM) for the dynamic analysis of jointed structures with resolved contact topography. In particular, the scale-dependent advantages of the Boundary Element (BE) and Finite Element (FE) methods are leveraged through a coupling consistent to the principle of virtual work. While the BE model resolves the contact topography exploiting elastic half-space theory, a relatively coarse FE model represents the dynamics of the nominal bulk structure. The developed MSM is validated numerically against full-FE simulations and experimentally against shaker tests. The results demonstrate excellent predictive accuracy compared to the reference while providing substantially improved numerical robustness and reducing computation times by up to five orders of magnitude.