Vibrational analysis of glass harp and its tone control

Abstract

In this paper, we focus on the control of the tone of a glass harp during the process of manufacturing, and on the analysis of the vibration of the glass harp using a finite element method. First, the effect of various factors on results is studied, such as the element type that enables a good geometries approximation and the number of divisions on the accuracy of mode frequencies. Second, we examine how each mode frequency changes with the bulge of the glass harp. The results demonstrate that the use of a bulge is effective in controlling the pitch and the timbre. Third, the pitch can be varied over a wide range by changing the bulge of the cup. In particular, it can be finely adjusted by cutting the inside bottom of the cup so as to form of a small circular groove instead of using a conventional method, which involves cutting the outside of the cup.