Experimental and simulated exploration of structural deflections and acoustic waves of guitar top plates

J. Alejandro Torres ^a J. Luis Villarreal ^b and R. Ramírez^b

^a Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México Campus Juriquilla, Boulevard Juriquilla No. 3001 Juriquilla, Querétaro, 76230, México.

^b Departamento de Visualización Científica Dirección General de Computo y de Tecnologías de Información y Comunicación Universidad Nacional Autónoma de México, México.

Abstract

The focus of this paper is to describe complex theoretical concepts about vibration and acoustics, considering experimental and computational tools. Some modal behaviors of a structure were explained. First, an experiment was designed to naked eye visualization of mode shapes in a thin film. Later, simulated deflections of a guitar top plate model were explored. This exploration was done through original scientific visualization software. Moreover, the developed computational tool was essential illustrating behaviors that used to be hard to visualize: acoustic waves. Sound radiation data were calculated from the vibration of the top plate model. These data were sliced to detect acoustic wavefronts and directivity patterns. Experimental and computational procedures developed in this work were useful illustrating vibroacoustic behaviors. Mode shapes and natural frequencies in the thin film experiment were clearly detected. Scientific visualization software showed ability to display vibroacoustic information in high density, with much semantic substance and time savings. The experiment can be easily implemented in a classroom, and the software can be used to explore other kind of data in standard Visualization Tool Kit format.

Keywords: Guitar; mode shapes; teaching physics.

PACS: 43.40.At; 68.60.Bs; 01.50.Pa

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Acknowledgments

The first author would like to thank to the Programa de Becas Posdoctorales of the National Autonomous University of México as partial sponsor of this work.

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