Non-Hertzian behavior in binary collisions of plastic balls derived from impact acoustics

This paper presents slight deviations from Hertz's impact law, inferred from acoustic signatures of polypropylene ball collisions. An impact acoustics model is used to fit the acoustic data. The model is built upon a generalized relationship between impact force (F) and deformation (xi) of the...

Full description

Saved in:
Bibliographic Details
Published inThe Journal of the Acoustical Society of America Vol. 128; no. 1; p. 132
Main Authors Riner, Joshua, Petculescu, Andi
Format Journal Article
LanguageEnglish
Published United States 01.07.2010
Subjects
Acceleration
Acoustics
Elastic Modulus
Energy Transfer
Models, Theoretical
Polypropylenes - chemistry
Pressure
Sound
Sound Spectrography
Time Factors
Vibration
Online AccessGet more information

Cover

More Information
Summary:This paper presents slight deviations from Hertz's impact law, inferred from acoustic signatures of polypropylene ball collisions. An impact acoustics model is used to fit the acoustic data. The model is built upon a generalized relationship between impact force (F) and deformation (xi) of the form F=kappaxi(alpha). Agreement with experiment is reached when alpha and kappa differ from Hertz's values by -6.25% and +1%, respectively. The difference is ascribable to non-idealities such as slight material inhomogeneities, impact-point asymmetry, plasticity etc. Also, the collision energy released as sound, which is usually dismissed as negligible, is derived from data fitting. The acoustic-to-incident energy ratio, dependent on impact duration, is constrained to be on the order of 100 ppm.
ISSN:1520-8524
DOI:10.1121/1.3438477