Bridge J.

The steelpan is an instrument which was developed in Trinidad and Tobago in the 1930’s. Each pan consists of the flat end of an oil drum hammered into a shallow well upon which quasi-ellipsoidal notes are marked out. Each note is acoustically separated from its neighbours by indenting its borders with a steel punch (grooving). The final stage of the steelpan manufacture involves careful tuning of the playing surface by carefully adjusting the geometry of each note. When a properly tuned note is impacted, a variety of interacting and non-interacting localized modes vibrate, yielding a rich playing sound. Frequency spectra reveal that as many as ten of a note’s overtones are “close to” integer multiples of the fundamental frequency, thus yielding a strong sense of pitch when being played. To date, the development of the steelpan has been mostly by trial and error. In order to optimize the manufacturing and tuning processes of the pan, it is important that a mathematical model of the system be developed, which can assist in understanding how the material properties, the forming processes and the geometric properties of each note affect the sounds produced by the steelpan. In the current work, the dynamic response of the tenor steelpan (which has 28 playing notes from D4 to F6) is investigated using the finite element method. Shell elements are used to model the steelpan, since it is thin in the direction normal to its doubly curved playing surface. Upon modeling the individual notes with appropriate boundary conditions, general relationships were obtained by independently varying the initial stress in the note and the following geometric properties: aspect ratio, surface area, height, thickness. The general results observed correspond well with previously obtained experimental data.