Economic Control of Quality of Manufactured Product.

The paper presents a gradient-based topology optimization formulation that allows to solve acoustic–structure (vibro-acoustic) interaction problems without explicit boundary interface representation. In acoustic–structure interaction problems, the pressure and displacement fields are governed by Helmholtz equation and the elasticity equation, respectively. Normally, the two separate fields are coupled by surface-coupling integrals, however, such a formulation does not allow for free material re-distribution in connection with topology optimization schemes since the boundaries are not explicitly given during the optimization process. In this paper we circumvent the explicit boundary representation by using a mixed finite element formulation with displacements and pressure as primary variables (a u/p-formulation). The Helmholtz equation is obtained as a special case of the mixed formulation for the elastic shear modulus equating to zero. Hence, by spatial variation of the mass density, shear and bulk moduli we are able to solve the coupled problem by the mixed formulation. Using this modelling approach, the topology optimization procedure is simply implemented as a standard density approach. Several two-dimensional acoustic–structure problems are optimized in order to verify the proposed method. Copyright © 2006 John Wiley & Sons, Ltd.

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Topology optimization of acoustic-structure interaction problems using a mixed finite element formulation

Optimization of locally resonant acoustic metamaterials on underwater sound absorption characteristics

An investigation into feasibility of impingement heat transfer and acoustic abatement of meso scale synthetic jets

Finite element acoustic simulation based shape optimization of a muffler

Shape optimization on constrained single-layer sound absorber by using GA method and mathematical gradient methods

Numerical studies on venting system with multi-chamber perforated mufflers by GA optimization

Shape optimization of multi-chamber cross-flow mufflers by SA optimization

GA optimization on multi-segments muffler under space constraints

While the space volume of mufflers in a venting system gets constrained, shape optimization to maximize the muffler's performance becomes important and essential. This paper presents a genetic algorithm (GA) for the optimal shape design of mufflers.

The four-pole matrix method which was adopted in evaluating the acoustic performance of sound transmission loss (STL) is used in conjunction with the GA techniques. Case studies of the full band noise inside a venting system are exemplified by the reactive mufflers. Before the GA operation, several examples are tested and compared with the experimental data for accuracy check of the mathematical models. Consequently, GA can provide a quick and effective way for a muffler design work. Copyright © 2005 John Wiley & Sons, Ltd.

Ying-Chun Chang

Papers

Shape optimization on constrained single-layer sound absorber by using GA method and mathematical gradient methods

Numerical studies on venting system with multi-chamber perforated mufflers by GA optimization

Shape optimization of multi-chamber cross-flow mufflers by SA optimization

GA optimization on multi-segments muffler under space constraints

Numerical studies on constrained venting system with reactive mufflers by GA optimization