ASA 126th Meeting Denver 1993 October 4-8

4aSA4. Optimization of acoustical treatments with respect to dynamic compliance and static deformation under load.

Edward M. Kerwin, Jr. Nathan C. Martin Jeffrey A. Zimmer Jeffrey A. Doughty

Bolt Beranek and Newman, Inc., 70 Fawcett St., Cambridge, MA 02138

This paper presents a method of organizing information on two important performance measures of an acoustical treatment or element whose dynamic compliance and total displacement under static loading are of concern. The method is simple but quite general, and allows one to select the optimum treatment from a set of candidates, or to modify and optimize a given candidate. The two normalized performance metrics are the unit-volume dynamic compliance q, and a unit thickness-deformation parameter V=(epsilon)/q, where (epsilon) is the static thickness strain under load. The optimization process utilizes these unit-volume parameters under the assumption that the required total dynamic compliance q[sub tot] will be specified, although its numerical value need not be known ahead of time. In this case it follows that V is always proportional to the total thickness and total deformation under load. In addition the V-q presentation has proven helpful in developing physical insight into the behavior of various compliant treatments. [Work supported by Office of Naval Research.]