Port-Hamiltonian Fluid-Structure Interaction Modeling and Structure-Preserving Model Order Reduction of a Classical Guitar

TL;DR

This work develops a fluid-structure interaction model for a classical guitar in port-Hamiltonian form, enabling energy-based interconnection, passivity, and stability properties essential for reliable multi-query simulations. A detailed FE-based forward model couples elastic guitar plates with enclosed air, then is transformed into a symmetric pH descriptor suitable for structure-preserving MOR. Through an extensive comparison of projection methods and basis-generation techniques, the authors show that pH-preserving and energy-stable MOR consistently outperform non-structure-preserving approaches, with a symplectic SVD-like basis delivering superior accuracy at smaller ROM sizes. The transient time-domain simulations demonstrate the practical viability of these reduced models for real-time or multi-query contexts, leveraging an Abaqus–MATLAB workflow. The findings promote robust, efficient MOR for complex multi-physics instruments and similar FSI systems, with future work on error estimation and richer parameterization.

Abstract

A fluid-structure interaction model in a port-Hamiltonian representation is derived for a classical guitar. We combine the laws of continuum mechanics for solids and fluids within a unified port-Hamiltonian (pH) modeling approach by adapting the discretized equations on second-order level in order to obtain a damped multi-physics model. The high-dimensionality of the resulting system is reduced by model order reduction. The article focuses on pH-systems in different state transformations, a variety of basis generation techniques as well as structure-preserving model order reduction approaches that are independent from the projection basis. As main contribution a thorough comparison of these method combinations is conducted. In contrast to typical frequency-based simulations in acoustics, transient time simulations of the system are presented. The approach is embedded into a straightforward workflow of sophisticated commercial software modeling and flexible in-house software for multi-physics coupling and model order reduction.

Figures (11)

• Figure 1: classical guitar
• Figure 2: workflow diagram
• Figure 3: sectional view of the FEM multi-physics model of a classical guitar
• Figure 4: meshed top plate
• Figure 5: meshed fluid