The Semi-Analytical Finite-Element (SAFE) method represents one of the most established numerical approaches for predicting the propagation of elastic waves in one-dimensional structures of arbitrary cross-sections. Its implementation in the commercial finite-element software COMSOL Multiphysics has been proposed in recent years; however, it is limited to only the free wave propagation for computing dispersion curves. To overcome this limitation, this paper proposes an extension of this approach that combines COMSOL and its Livelink for Matlab tool. This enables the extraction from COMSOL of the assembled mass and stiffness SAFE matrices to solve problems of both free and forced wave propagation in the Matlab environment. The resulting customised software takes advantage of both the potential of commercial FE software and the power of Matlab without worrying about compatibility issues. A model of a simply supported plate strip and that of a more complex geometry are implemented to validate, respectively, the SAFE matrix extraction procedure and the implemented forced response formulation. The results agree well with corresponding analytical and numerical results validating the proposed implementation of the SAFE method.

In-vacuo tuneable structured fabrics represent an innovative class of smart materials capable of modulating their mechanical and dynamic properties through controlled confinement pressure. When arranged in beam-like configurations, these structures can operate as vacuum-controlled waveguides with pressure-dependent stiffness and dispersion characteristics. This paper presents a preliminary investigation of elastic wave propagation in a beam-like vacuum-controlled tuneable structured fabrics under variable confinement pressures. A prototype was designed and fabricated to assess both the technical feasibility and manufacturability. Experiments were conducted using a correlation-based wavenumber identification technique to characterise wave behaviour. A one-dimensional wave finite element model was implemented in COMSOL Multiphysics, employing Floquet boundary conditions and Hertzian contact theory with a scaling factor to account for contact multiplicity. Computed dispersion curves at 20 kPa and 80 kPa confinement pressures show qualitative agreement with experimental measurements. Results demonstrate that increasing confinement pressure enhances structural stiffness and shifts dispersion branches toward higher frequencies. Wave mode shape analysis confirms multiple bending and longitudinal modes consistent with classical beam theory. These findings suggest that in-vacuo structured fabrics can be suitably employed as programmable linear and homogenous metamaterials for vibration control.