This paper addresses the issue of transient structural dynamics in the higher-frequency range by an energetic approach. Its main purpose is to propose an alternative equation [Eq. (10) of the paper] to the usual diffusion equation [Eq. (1) of the paper] which is at the basis of the vibrational conductivity analogy of high-frequency structural dynamics. In Sec. 2.2, the authors try to justify their results (presented in Sec. 2.1) on the basis of the transport theory presented in 1 and applied to the case of randomly heterogeneous Mindlin plates in 2 or thick shells in 3. This tentative “justification” draws several comments.

1. It is clear from transport equations (22) and (23) that $W+$ and $W−$ depend on the wave vector k=|k|k^. Then the space–time energy density $Wx,t$ is obtained by integrating the half-sum...
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