Vibration and sound radiation of solid wood and tubular metal baseball bats as a function of ball–bat location

• Published in: The Journal of the Acoustical Society of America 2004-10, Vol.116 (4_Supplement), p.2601-2601
• Main Authors: Collier, Robert D., Kaliski, Kenneth, Sherwood, James A.
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4808680

The ‘‘crack of the bat’’ is an important part of the game of baseball played with solid wood bats. The spectral characteristics of the radiated sound depend on the location of the ball–bat impact location along the length of the barrel and the resulting bat vibration. Balls hit on the sweet spot generally are hit harder and result in a distinct and recognizable ‘‘crack’’ sound. On the other hand, balls hit in on the handle or off the end of the barrel result in different modes of vibration and low-frequency radiation, i.e., a ‘‘thunk-like’’ sound. Analytical predictions and modal analyses, supported by both laboratory and field measurements, provide a more comprehensive picture of bat vibration and radiated sound relationships. Comparisons are made with tubular metal bats which exhibit the narrow-band signature due to excitation of the cylindrical breathing (bell) modes which are essentially independent of hit location. The differences in bat vibration and sound radiation can provide important clues for baseball players in the field.