PRELIMINARY STUDY OF HOLLOW PIPE WITH AN UNDERCUT AS PERCUSSION INSTRUMENT

This work investigates the possibility of using steel hollow pipe with an undercut to make a new type of percussion instrument. From traditional bamboo percussion instruments found in Taiwan or elsewhere, the bamboo geometry is a hollow tube structure generally with the undercut. This work formulates a basic geometry model with specific dimension variables for the hollow pipe with an undercut in the middle. A stainless steel pipe is first chosen to identify its materials properties and used to manufacture the special pipe percussion instrument. A trial study on determining the dimension of the pipe and its undercut is performed to obtain the initial pipe geometry design, in particular for Note A5 with the pitch frequency 880 Hz. Both theoretical modal analysis (TMA) and experimental modal analysis (EMA) are conducted on the pipe, respectively. The obtained structural modal parameters reveal very good agreement between experiments and analysis. The percussion sound of the pipe with the undercut is also studied by spectral analysis. Results show the fundamental frequency of the pipe matches the pitch frequency of Note A5 very well. There are several overtone frequencies over the fundamental frequency having integer ratios. This is known as harmonic sound characteristic that makes the percussion sound of the pipe in harmony and pleasantness. The optimum design for different pitch frequencies of musical notes can be developed accordingly base on the geometry model and under investigation to design a new type of percussion instrument for the hollow pipe with undercut.