Influence of thickness profile and bracing pattern in the radiation patterns of archtop guitars

In this study, we investigate the influence of the thickness profile of the top plate and bracing pattern on the vibrational and acoustic properties of archtop guitars through finite element simulations. Starting from a laser scan of a real archtop guitar, we develop a fully parametric three-dimensional model of the guitar body. The thickness profile is parametrically controlled by adjusting the lower surface while maintaining the fixed upper surface. Both geometric and numerical modeling techniques are used to analyze the mechanical behavior of the guitar, including modal analysis, and acoustic behavior, focusing on sound intensity, and directivity. Our simulations reveal that variations in the thickness profile significantly affect the modal response and sound radiation patterns. In particular, we highlight the relationship between the vibrational modes and radiation patterns, demonstrating that changes in thickness lead to shifts in eigenfrequencies and variations in radiated sound pressure levels. The models and simulation code are made openly available to facilitate further research in the acoustics of archtop guitars.