Topology optimization of acoustic mechanical interaction problems: a comparative review

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This article propose a generalized shape optimization method for transient coupled acoustic-mechanical interaction problems. The transient problem formulation allows to optimize for a broadband frequency content and the possibility to investigate transient phenomena such as pulse shaping. Throughout the work, the geometry is defined with the help of a nodal-based design field, for which its zero-level contour describes the interface between acoustic and structural domains. The approach utilizes a fixed background mesh to represent the geometry and a cut element immersed boundary method for the physical modeling. This modeling approach provides accurate solutions to the strongly coupled governing equations based on a special integration scheme. The optimization problem is solved using a gradient-based optimizer and employs a fully discrete adjoint approach for calculating the sensitivity information. A numerical examination on the accuracy of the sensitivity analysis compares the fully discrete gradients to the commonly used semidiscrete adjoint approach for transient optimization revealing the importance of consistent sensitivities. The transient design formulation is validated on a 2D benchmark problem concerning the design of a time-harmonic acoustic partitioner. The developed framework is then applied for the design of vibroacoustic pulse shaping devices to demonstrate control of a transient phenomena.

Section: Sensitivity Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Generalized shape optimization of transient vibroacoustic problems using cut elements

Dilgen

Aage

2021

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“…Herein, the satisfaction of Equation (12) has been reflected in the derivation process. Finally, by taking into account the relationships (11), (18), and Ω 1 = 0, we take the volume integration of Equation (10) over a unit cell to have the following homogenized wave equation:…”

Section: F I G U R E 1 Concept Of Homogenization For Bidirectional Unmentioning

confidence: 99%

“…The topology optimization, which was originally proposed by Bendsøe and Kikuchi, is the most promising technique because of its flexibility among some classes of structural optimization. In fact, a considerable number of studies has been made on the development of the topology optimization over the past few decades (see Sigmund and Maute, Munk et al, Dilgen et al, and references therein).…”

Section: Introductionmentioning

confidence: 99%

Isogeometric topology optimization of anisotropic metamaterials for controlling high‐frequency electromagnetic wave

Nishi

Yamada

Izui

et al. 2019

Summary This study presents a level set–based topology optimization with isogeometric analysis (IGA) for controlling high‐frequency electromagnetic wave propagation in a domain with periodic microstructures (unit cells). The high‐frequency homogenization method is applied to characterize the macroscopic high‐frequency waves in periodic heterogeneous media whose wavelength is comparative to or smaller than the representative length of a unit cell. B‐spline basis functions are employed for the IGA discretization procedure to improve the performance of electromagnetic wave analysis in a unit cell and topology optimization. Also, to keep the same order of continuity on the periodic boundaries as on other element edges in the domain, we propose the extended domain approach, while incorporating Floquet periodic boundary condition (FPBC). Two types of optimization problems are taken as examples to demonstrate the effectiveness of the proposed method in comparison with the standard finite element analysis (FEA). The optimization results provide optimized topologies of unit cells qualified as anisotropic metamaterials with hyperbolic and bidirectional dispersion properties at the macroscale.

“…One approach to achieving these goals is to modify the geometry or the topology of the structure since this influences the structure's acoustic coupling with surrounding fluid, and its vibrational characteristics. As discussed later in this section, there is large body of work devoted to developing efficient and robust techniques for solving the structural acoustic topological optimization problem 8 . An alternative approach is to optimize the elastic properties of the structure within a subdomain.…”

Section: Introductionmentioning

confidence: 99%

Material parameter optimization for interior and exterior fluid‐structure acoustic problems

Ramaswamy

Dey

Oberai

2020

Summary We present an efficient adjoint‐based framework for computing sensitivities of quantities of interest with respect to material parameters for coupled fluid‐structural acoustic systems with explicit interface coupling. The fluid is modeled using the Helmholtz equation and the structure is modeled using the Navier‐Cauchy equations. Sensitivities are used to drive a gradient based optimization algorithm to solve important problems in structural acoustics, viz noise minimization and vibration isolation. For each problem, we consider two different priors: one where the optimal solution has a smooth variation and another with a bimaterial distribution. These priors are imposed with the help of suitable regularization terms. The effectiveness of this approach is demonstrated on both interior and exterior structural acoustic problems.