| Popis: |
Lightweight porous acoustic multilayer trim components have traditionally been specified in terms of sound absorption and sound transmission loss performance targets. Importantly, the material specification of the trim component developed only for absorption and sound transmission loss may be suboptimal in terms of, e.g., sound radiation behavior. This highlights the necessity for accurate, computationally efficient, and robust simulation method, which should form an integral part of a multidisciplinary optimization tool. In addition, for such optimization to be physically meaningful the design parameters used should be based on relations between microstructural dimensions and properties, and the corresponding macroscopic parameters describing porous materials. This paper discusses recent results from research focused on the parametrization of porous foams, i.e., continuous links between micro‐dimensions, elasticity, density, and flow resistivity, used in higher order 3‐D finite element simulations of multilayer components for structural‐acoustic applications. In addition to the microdimensions, also the thicknesses of individual layers have been used as design parameters, with the overall weight as the design objective. Acoustic and vibration targets, velocity of the radiating surface, radiation efficiency, transmission, etc., as well as upper and lower bounds of the microdimensions, have been used as constraints. |
