Equation-Free Digital Twins for Nonlinear Structural Dynamics

Fuente: arXiv
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Main Authors: Abaei, Mohammad Mahdi, BahooToroody, Ahmad, Polojärvi, Arttu, Remes, Heikki, Tygesen, Ulf Tyge, Suominen, Mikko, Beer, Michael
Format: Preprint
Published: 2026
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author Abaei, Mohammad Mahdi
BahooToroody, Ahmad
Polojärvi, Arttu
Remes, Heikki
Tygesen, Ulf Tyge
Suominen, Mikko
Beer, Michael
author_facet Abaei, Mohammad Mahdi
BahooToroody, Ahmad
Polojärvi, Arttu
Remes, Heikki
Tygesen, Ulf Tyge
Suominen, Mikko
Beer, Michael
contents Monitoring high-dimensional engineering structures in extreme environments is limited by non-stationary excitation, nonlinear structural kinematics, and stochastic forcing. Traditional model-based and black-box data-driven methods often struggle to resolve these dynamics in real time, particularly under sensor failure or partial observability. This paper introduces a rank-optimized digital twin framework based on Koopman operator theory, Hankel-matrix embeddings, and dynamic mode decomposition. By lifting operational data into a linear invariant subspace, the method enables autonomous, input-blind reconstruction of structural states without requiring a priori mass or stiffness matrices. The framework is validated on an NREL 5MW spar-buoy floating offshore wind turbine, representing a challenging coupled aero-hydro-servo-elastic system. Results show that the rank-optimized Koopman-Hankel manifold separates structural resonances from deterministic 3P rotor harmonics under colored noise, where standard subspace identification can be unreliable. A rolling-horizon virtual sensing strategy achieves high-fidelity reconstruction at critical structural hotspots, with coefficient of determination greater than 0.95 at 1 Hz data assimilation and accuracy exceeding 0.99 at higher sampling rates. By estimating a physical Lyapunov time of approximately 1.0 s, the study defines the predictability horizon associated with the system information barrier. The proposed framework provides a computationally efficient and resilient digital twin approach for real-time identification and virtual sensing of complex structural dynamics.
format Preprint
id arxiv_https___arxiv_org_abs_2605_00950
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Equation-Free Digital Twins for Nonlinear Structural Dynamics
Abaei, Mohammad Mahdi
BahooToroody, Ahmad
Polojärvi, Arttu
Remes, Heikki
Tygesen, Ulf Tyge
Suominen, Mikko
Beer, Michael
Signal Processing
Machine Learning
Systems and Control
Monitoring high-dimensional engineering structures in extreme environments is limited by non-stationary excitation, nonlinear structural kinematics, and stochastic forcing. Traditional model-based and black-box data-driven methods often struggle to resolve these dynamics in real time, particularly under sensor failure or partial observability. This paper introduces a rank-optimized digital twin framework based on Koopman operator theory, Hankel-matrix embeddings, and dynamic mode decomposition. By lifting operational data into a linear invariant subspace, the method enables autonomous, input-blind reconstruction of structural states without requiring a priori mass or stiffness matrices. The framework is validated on an NREL 5MW spar-buoy floating offshore wind turbine, representing a challenging coupled aero-hydro-servo-elastic system. Results show that the rank-optimized Koopman-Hankel manifold separates structural resonances from deterministic 3P rotor harmonics under colored noise, where standard subspace identification can be unreliable. A rolling-horizon virtual sensing strategy achieves high-fidelity reconstruction at critical structural hotspots, with coefficient of determination greater than 0.95 at 1 Hz data assimilation and accuracy exceeding 0.99 at higher sampling rates. By estimating a physical Lyapunov time of approximately 1.0 s, the study defines the predictability horizon associated with the system information barrier. The proposed framework provides a computationally efficient and resilient digital twin approach for real-time identification and virtual sensing of complex structural dynamics.
title Equation-Free Digital Twins for Nonlinear Structural Dynamics
topic Signal Processing
Machine Learning
Systems and Control
url https://arxiv.org/abs/2605.00950