Time-resolved strain and deformation measurement on the vibrating saxophone reed

Single-reed musical instruments, such as the saxophone, generate sound through a complex interplay between the mechanics of the reed and the hydrodynamic and acoustic pressure in the instrument mouthpiece. To understand this complex mechanism, experimental data are lacking. This paper presents full-field, time-resolved measurements of strain and displacement of a vibrating saxophone reed, measured under mimicked realistic playing conditions. It is found that strain along the length axis of the reed is mainly expansive, except in a small zone near the tip where it becomes compressive when the reed touches the front edge of the mouthpiece. At the instant in the vibration phase where the reed touches the mouthpiece, significant bending and compressive strain appear along the direction perpendicular to the reed axis. Strain magnitudes in both directions are similar, with absolute values of 0.1%. Full-field strain maps reveal subtle characteristics which are not revealed by displacement measurements. Bi-axial bending and strain may be an essential component in reed mechanics, which up till now has been fully neglected in modelling.