Different Definitions of Entropy for Statistical Energy Analysis

This paper explores several definitions of entropy that stem from the fields of statistical mechanics and thermodynamics for vibrating structures. This paper shows that these definitions are equivalent in the context of mechanically vibrating systems. However, one is more suitable for statistical energy analysis. This work is motivated by the usefulness of the entropy concept towards developing a framework for the statistical treatment of vibroacoustic systems. Specifically, entropy provides a thermodynamic framework to justify the methodology of statistical energy analysis.