ENERGY-FLOW ANALYSIS OF COUPLED BEAMS

Energy flow analysis (EFA) is an analytical tool for prediction of the frequency-averaged vibrational response of built-up structures at hig h audible frequencies. The procedure is based on two developments; fir st, the derivation of the partial differential equations that govern t he propagation of energy-related quantities in simple structural eleme nts such as rods, beams, plates, and acoustic cavities; and second, th e derivation of coupling relationships in terms of energy-related quan tities that describe the transfer of energy for various joints (e.g., beam-to-beam, rod-to-beam, plate-to-plate, structure-to-acoustic held coupling). In this investigation, the energy flow coupling relationshi ps at these joints for rods and beams are derived. EFA is used to pred ict the frequency-averaged vibrational response of a frame structure w ith a three-dimensional joint, where four wave types propagate in the structure. The predicted results of EFA are shows to be a good approxi mation of the frequency-averaged ''exact'' energetics, which are compu ted from classical displacement solutions. (C) 1998 Academic Press Lim ited.