🤖 AI Summary
Existing graph neural networks (GNNs) have been employed as surrogate models in computational fluid dynamics, yet their application to dynamic structural mechanics—particularly wave-dominated problems—remains unexplored. This work introduces GNSS, the first GNN-based surrogate for dynamic structural simulation. Methodologically, GNSS features: (1) node-fixed local coordinate systems to eliminate numerical cancellation in velocity estimation; (2) a sign-aware loss function to suppress phase drift during long-horizon rollout; and (3) wavelength-aware graph connectivity to optimize topological structure. Built upon an encode-process-decode architecture, it integrates finite-difference-based velocity estimation with physics-informed graph construction. Evaluated on a 50-kHz pulsed excitation beam benchmark, GNSS achieves hundreds of high-fidelity time steps with strong generalization to unseen dynamics. It outperforms explicit finite-element solvers significantly in inference speed while preserving spatiotemporal accuracy.
📝 Abstract
Graph Neural Networks (GNNs) have recently been explored as surrogate models for numerical simulations. While their applications in computational fluid dynamics have been investigated, little attention has been given to structural problems, especially for dynamic cases. To address this gap, we introduce the Graph Network-based Structural Simulator (GNSS), a GNN framework for surrogate modeling of dynamic structural problems.
GNSS follows the encode-process-decode paradigm typical of GNN-based machine learning models, and its design makes it particularly suited for dynamic simulations thanks to three key features: (i) expressing node kinematics in node-fixed local frames, which avoids catastrophic cancellation in finite-difference velocities; (ii) employing a sign-aware regression loss, which reduces phase errors in long rollouts; and (iii) using a wavelength-informed connectivity radius, which optimizes graph construction.
We evaluate GNSS on a case study involving a beam excited by a 50kHz Hanning-modulated pulse. The results show that GNSS accurately reproduces the physics of the problem over hundreds of timesteps and generalizes to unseen loading conditions, where existing GNNs fail to converge or deliver meaningful predictions.
Compared with explicit finite element baselines, GNSS achieves substantial inference speedups while preserving spatial and temporal fidelity. These findings demonstrate that locality-preserving GNNs with physics-consistent update rules are a competitive alternative for dynamic, wave-dominated structural simulations.