With the popularity of golfing, the marketing of golf clubs has been promoted in recent years. The purpose of this study is to investigate the sound effects of golf impact on different shapes and thicknesses of striking face of the golf club using the finite element method. The researcher found that the vibration model and the resonance frequency of golf club heads. In addition, the researcher used vibration modal analysis to generalize the golf head modes with the distribution of the sound pressure. He also used acoustic transient analysis to check the sound pressure level. Finally, the correlations among the sound pressure, sound pressure level and sound frequency of the golf club head impacts were administered. After all, the study findings provides golf head designers and producers with a reference for designing, revising and producing comfortable and qualified impact sounds of golf club heads.

Abstract This study aims to investigate the impact effect of varied thickness of the hitting surface and different shapes of the golf club head. The researcher integrated the computer-aided design software Pro/ENGINEER and finite element analysis software LS-DYNA to do the club head design and impact analysis. The researcher had developed five different shapes and eight different thicknesses of hitting surface of the club head model to compare the ball speed and the sweet spot of the hitting surface. He found that ball speed had increased as the hitting surface is enlarged, both laterally and vertically. He also found that thicker center surface and decreasing thickness to the rim of the thickness of the hitting surface is a better design club head. Finally, he made suggestions about the scientific information of the shape and the surface thickness of the golf club head for the designer to develop a suitable club head.

The center of gravity (CG) in the golf club head is crucial to the launch angle, launch velocity and spin of golf balls after the golf impact. The CG locations in this study refer to the depth of CG, height of CG and distance of CG, which were determined by the change of shell thickness of a golf club head. By means of the finite element method (FEM), the researcher analyzed the impact process for golf balls and golf head clubs. Then he discussed the relationship between club heads and ball behaviors after impact. He also simulated the trajectory by the numerical method on the basis of the impact results of the golf ball. To sum up, a longer carry was generalized by deeper CG, lower CG and higher loft angle for a golfer with a slow club head speed. A shallower CG, higher CG and lower loft on a club head for a golfer with a fast club head speed were also verified in this study. Finally, a series of impacts produced by FEM and numerical method were generalized. Specifically, the method can be used to predict the flying distance of golf ball. It also can help predict the proper CG locations for golf club head designing.

The purpose of this study is to investigate the function of the different structural designs of golf club head models (including a deep head, a shallow back, and a shallow head) and to get the optimum golf club head through the software simulation. By means of software SolidWorks, the researcher draws three main club head models. The C ++ was used for a linear programming to control the golf club head thickness including an impact face, a crown, a sole, a toe and a heel under the definite weight. The simulation also helps adjust the center of gravity position of the golf club head and integrates with the finite element method software LS_Dyna in analyzing the impact procedure between the golf club head and the golf ball. In addition, the researcher preceded the analysis by replacing the crown surface as carbon fiber reinforcement polymers (CFRP). He also investigated the off-centered hit effects through the impact analysis. It is expected that study findings can be extracted. Through the simulation of the hit effects, the golf club head designers will be inspired to create more effective golf club heads.

Abstract Background: Golf is a sport with a growing focus on the physical aspect of the game and its relationship to performance. Studies have determined a correlation between club head speed and performance in golf. Rotational power has proven to be an important factor for the club head speed. By examining the relationship between club head speed and rotational power, researchers has found that rotation power on the golfers dominant side have a moderate to high correlation with club head speed. Previous research has mostly investigated the peak rotational power on the dominant side. Furthermore, additional research is needed to examine the bilateral strength and its relationship to club head speed. Aim: The aim of this study was to examine the correlation between peak trunk rotational power and club head speed in elite golfers, and also to study the impact of bilateral rotational strength on club head speed. Methods: The study included 27 elite golf players (21 males, 6 females) age 19±2 years. The subjects attended two sessions where the first session included a club head speed test and the second session a rotation power test in the Quantum machine. The rotational peak power ratio (dominant/non-dominant side) were ranged from 1-27 (the closer to 1, the higher order) to study a linier relationship with club head speed. Spearman’s nonparametric rank correlations coefficient (rs) was used since the data was not normally distributed. Results: There was a moderate correlation between peak trunk rotational power on the dominant side and club head speed ( rs=0.58, p=0.01). The correlation between the peak trunk rotational powers on the dominant and non- dominant side was high, rs=0.82 (p=0.01). There were no significant correlation found between the ranged rotational peak power ratio and club head speed (rs=0.30, p=0.1). Conclusion: The current study found a slightly lower correlation between peak trunk rotational power and club head speed than found in earlier studies. The golfers in this study had symmetric strength in the trunk, other studies have shown that the rotational strength in golfer´s dominant side were higher than of the non- dominant side. The result of this study indicates that balance between the sides not necessarily has a relationship with how high the golfer’s club head speed is. Future research is needed to analyze the quadratic correlation between ratio and club head speed on a more advanced level. The results of this study can, if validated, be used for further researching and understanding of club head speed and golf performance.

The purpose of this study is to integrate the efficiency of the computer-aided design software Pro Engineer and the finite element analysis software LS-DYNA on the structural design of the golf club head. By means of the parametric design characteristics of Pro Engineer, various thickness and different shapes of the golf club head have been studied. The impact model will extract the ball velocities and spins for a given hit location on the club face which is analyzed by the software LS-DYNA. After that, the factors for influencing the dynamic analysis, such as the thickness and the shape of the hitting face, the off-center hitting, the ball velocity and spin, the stress distribution, and stress propagation in the head are further identified and measured. Finally, the effects of the factors described above have been analyzed quantitatively to investigate the maximum velocity of the ball and the sweet spot of the golf club head.