3101 A design method for micro-structure of poroelastic sound-absorbing media by the homogenization method

As a new type of acoustic metamaterial, the pentamode material has extensive application prospect in controlling acoustic wave propagation because of its fluid properties. Firstly, a kind of pentamode material unit cell is designed, which is a two-dimensional honeycomb truss structure. Then, the asymptotic homogenization method is used to calculate static parameters of the unit cell, and also the influence of the geometric parameters and material composition of the unit cell on its mechanical properties is studied. Besides, based on transformation acoustics and the design method of the cylindrical cloak proposed by Norris, an acoustic cloak with isotropic density and gradient elastic modulus is constructed by periodically assembling the unit cell to guide the wave to bypass obstacles. Finally, the full displacement field analysis is carried out to prove the stealth effect of the acoustic cloak.

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Topology optimization of micro structure of porous material to maximize dissipated energy by using homogenization method

The Proceedings of Design & Systems Conference ◽

10.1299/jsmedsd.2020.30.1106 ◽

2020 ◽

Vol 2020.30 (0) ◽

pp. 1106

Author(s):

Takashi YAMAMOTO ◽

Keisuke YAMAKAWA ◽

Daiji KATSURA ◽

Hideyuki YUKAWA ◽

Joji OHSHITA

Keyword(s):

Topology Optimization ◽

Porous Material ◽

Homogenization Method ◽

Dissipated Energy ◽

Micro Structure

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IMAGE SYNTHESIS OF METAL FOAM MICRO-STRUCTURE WITH THE USE OF WANG TILES

Acta Polytechnica CTU Proceedings ◽

10.14311/app.2018.15.0142 ◽

2018 ◽

Vol 15 ◽

pp. 142-147

Author(s):

Lukáš Zrůbek ◽

Martin Doškář ◽

Anna Kučerová ◽

Marcela Meneses-Guzmán ◽

Francisco Rodríguez-Méndez ◽

...

Keyword(s):

Recent Work ◽

Metal Foam ◽

Design Method ◽

Image Synthesis ◽

Cellular Materials ◽

Planar Domain ◽

Micro Structure ◽

Wang Tiles ◽

Additional Step ◽

Respective Number

<p>In this paper we present our recent work focused on the analysis of the abilities of Wang Tiles method and Automatic tile design method to synthesize the micro-structure of cellular materials, especially particular type of metal foam.</p><p>Wang Tiles method stores and compress the micro-structure in a set of Wang Tiles and by the means of stochastic tiling algorithms the planar domain is reconstructed. The used tiles are created by the Automatic tile design method from respective number of small specimens extracted from the original micro-structure image. As an additional step the central areas of automatically designed tiles are patched to suppress the influence of repeating tile edges (and relevant tile quarters) on inducing artifacts. In the presented analysis the performance of raw and patched tiles of different sizes in conjunction of various tile sets is investigated.</p>

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Optimal Structural Design of Compliant Mechanisms Considering a Quantitative Displacement Constraint

Volume 2: 24th Design Automation Conference ◽

10.1115/detc98/dac-5580 ◽

1998 ◽

Author(s):

Susumu Ejima ◽

Shinji Nishiwaki ◽

Minako Sekiguchi ◽

Noboru Kikuchi

Keyword(s):

Elastic Deformation ◽

Structural Design ◽

Design Theory ◽

Compliant Mechanisms ◽

Design Method ◽

Homogenization Method ◽

Two Dimensional ◽

Material Density ◽

The Past ◽

Structural Design Optimization

Abstract Compliant mechanisms are a relatively new breed of jointless mechanisms in which the elastic deformation is intended to be a source of motion. In the past, flexible structural design optimization was considered only for the direction of the flexible point by using the material density or the homogenization method to identify the optimum layout. Here we shall extend this design theory to the case of a two dimensional design for compliant mechanisms which can specify the amount of deformation of the flexible portion. Finally, some examples are presented to confirm that the verification of optimal configuration using an image-based design method.

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Implicit Formulation of Homogenization Method for Periodic Elastoplastic Solids

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.340-341.1055 ◽

2007 ◽

Vol 340-341 ◽

pp. 1055-1060

Author(s):

Takashi Asada ◽

Nobutada Ohno

Keyword(s):

Tensile Loading ◽

Homogenization Method ◽

Present Formulation ◽

Micro Structure ◽

Displacement Fields ◽

Homogenization Problem ◽

Unit Cells ◽

Initial Setting

In this study, to determine incremental, perturbed displacement fields in periodic elastoplastic solids, an incremental homogenization problem is fully implicitly formulated, and an algorithm is developed to solve the homogenization problem. It is shown that the homogenization problem can be iteratively solved with quadratic convergences by successively updating strain increments in unit cells, and that the present formulation allows versatility in the initial setting of strain increments in contrast to previous studies. The homogenization algorithm developed is then examined by analyzing a holed plate, with an elastoplastic micro-structure, subjected to tensile loading. It is thus demonstrated that the convergence in iteratively solving the homogenization problem strongly depends on the initial setting of strain increments in unit cells, and that quick convergences can be attained if the initial setting of strain increments is appropriate.

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Topology Optimization: A New Micro-Structure Based Design Domain Method

20th Design Automation Conference: Volume 2 — Robust Design Applications; Decomposition and Design Optimization; Optimization Tools and Applications ◽

10.1115/detc1994-0138 ◽

1994 ◽

Author(s):

Hae Chang Gea

Keyword(s):

Topology Optimization ◽

Mathematical Programming ◽

Shear Modulus ◽

Optimization Problems ◽

Homogenization Method ◽

New Method ◽

Design Domain ◽

Micro Structure ◽

Domain Method ◽

Programming Algorithms

Abstract Topology optimization is the most complicated problem in structural optimization. One common approach is to utilize the concept of the design domain, such as the homogenization method and the density function approach. In this paper, a new micro-structure based design domain method is proposed. This new method gives simple closed-form expressions for effective Young’s modulus and effective shear modulus in terms of phase properties and volume fractions. Using these simple relations, topology optimization problems can be formulated and solved using mathematical programming algorithms. Results of some design examples obtained from the new method are presented.

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