ENERGY FLOW ANALYSIS OF BARS AND BEAMS: THEORETICAL FORMULATIONS

Autor: Lase, Y., Ichchou, M. N., Jezequel, L.
Zdroj: Journal of Sound and Vibration; April 25, 1996, Vol. 192 Issue: 1 p281-305, 25p
Abstrakt: Two methods of predicting the energy behaviour of bars and beams are presented. The first method called the general energetic method (G.E.M.) simultaneously employs the total energy density, the Lagrangian energy density and the active and reactive energy flows. It is shown that this method is an “exact” formulation when compared to the classical displacement methods for bars and beams. The use of both Lagrangian energy density and reactive energy flow also proves useful in the study of some pure tone coupled problems. In addition, the (G.E.M.) gives rise to a second useful method called the simplified energy method (S.E.M.), when applying the space-averaging concept and the far-field hypothesis. The (S.E.M.) obtained, is analogous to the well known power flow method introduced by Nefske and Sung ‘1’ and investigated further by Wohlever and Bernhard ‘2’. This method is of great numerical interest and is well suited for predicting medium and high frequency dynamics. In this study, for both (G.E.M.) and (S.E.M.), some classical boundary conditions will be written in terms of energy variables and the feasibility of coupling two dissimilar bars and beams by using the G.E.M. will be shown.
Databáze: Supplemental Index