In the proposed work a complete elastic porous material theory will be used as a basis for developing the first two-dimensional acoustical finite element model of noise control foams. Although foams are widely used for passive control of aircraft and automobile interior noise, complete numerical models of those materials do not exist, thus limiting the design alternatives available to numerical analysts. The development of finite element foam models that are compatible with existing acoustical finite element codes would allow, for example, optimal design of high transmission loss fuselage treatments by using modern numerical techniques. To illustrate the utility of the proposed work, the transmission loss of finite, foam-lined fuselage sections will be calculated. In addition, a two-dimensional acoustical finite element model of "smart foam" will be developed, so allowing simulations of the latter's effectiveness for active control of vehicle interior noise. "Smart foams" are foam layers containing shaped piezoelectric membranes; by applying appropriate voltages to the membrane it may be possible to enhance the sound absorption and transmission properties of foam layers, particularly at low frequencies. The work will be performed over a period of six months by AAC personnel with assistance from personnel at Purdue University.The elastic-absorption finite element technology developed during Phase I ca be marketed as a complement to the general purpose FEM code that is currently being developed by Automated Analysis Corporation. It is also a valuable addition to established general purpose acoustic codes. It will promote active and passive noise control researches in the aerospace, automotive and defense industries.Finite Element Model, Elastic Porous Material, "Smart Foams"Phase 2 conversion
