A transient local energy approach as an alternative to transient sea: Waveand telegraph equations

This paper is concerned with the high-frequency dynamics of structures in t he time domain. In this frequency range, a differential equation governing the vibrational energy density is proposed. This simplified equation leads to the prediction of large scale space and time evolution of the energy qua ntities averaged over time, frequency and space. For one-dimensional undamp ed structures, the energy equation is the classical wave equation whereas i ts generalization for damped structures leads to a telegraph-type equation. The discussion is focussed on the comparison with the diffusion equation s ometimes encountered in the literature. (C) 2001 Academic Press.