Prediction of Impact Sounds of Golf Clubs

Abstract

    Golfers choose their clubs according to their feelings. The impact sound of the club with a ball greatly affects such feelings. Sound simulation of the impact sound is needed at the design stage, but it has been very difficult to simulate this using the commercial methods of the Finite Element Method (FEM) and the Boundary Element Method (BEM) . In our laboratory, this simulation is accomplished practically with the use of a personal computer. First, surface velocity is computed by the theory of Modal Analysis. Second, sound pressure is computed by the theory of the velocity potential method. Third, these data are inverse Fourier transformed to time domain data, which can then be listened to. This simulation is programmed using Fortran. The practicability of this program is examined by use of a simple model. Simulated surface velocity is compared with experimental values. They are found to be almost coincident, except for the higher frequencies, where they are less coincident. This is because in the high frequency domain FEM is not so accurate and identification of the modal damping ratio becomes difficult. In the comparison of sound pressure, also in the high frequency domain differences from the experiments still occur because of FEM error and experimental error. Next, the driver club without shaft is examined. The biggest resonance peak is simulated correctly and the sounds are found to be almost same, but higher modes are not as coincident.