The vibrational mode structure of a golf ball

Area of Science:

• Physics of Sports Equipment
• Acoustics and Vibrational Analysis

Background:

• Golf ball performance is influenced by its vibrational characteristics.
• Understanding these vibrations is key to optimizing ball design and playability.

Purpose of the Study:

• To determine the discrete vibration frequencies of golf balls.
• To characterize the mode patterns and excitation methods for these vibrations.
• To compare analytical and numerical models for predicting golf ball vibrational behavior.

Main Methods:

• Analytical calculations for homogeneous ball cores.
• Finite element numerical simulations for core and two-piece ball models.
• Investigated excitation by tangential (spin-producing) and radial impact forces.

Main Results:

• Identified two classes of vibration modes: acoustic (sound-radiating) and silent.
• Established correspondences between analytical and numerical results for low-frequency modes.
• Demonstrated that tangential forces excite both acoustic and silent modes, while radial forces excite only acoustic modes.

Conclusions:

• The study validates vibrational analysis for real golf balls.
• Results offer a basis for non-destructive measurement of elastic shear moduli.
• Potential for 'tuning' golf ball performance for specific clubs is highlighted.