Optically Transparent Flexible Broadband Metamaterial Absorber Based on Topology Optimization Design

A conformal metamaterial absorber with simultaneous optical transparency and broadband absorption is proposed in this paper. The absorptance above 90% over a wide frequency range of 5.3–15 GHz can be achieved through topology optimization combined with a genetic algorithm (GA). The broadband absorption can be kept at incident angles within 45° and 70° for TE mode and TM mode, respectively. In the meantime, by employing transparent substrates, including polyvinyl chloride (PVC) and polyethylene terephthalate (PET), good optical transmittance and flexibility can be obtained simultaneously. The experimental results agree well with the numerical simulations, which further validates the reliability of our design and theoretical analysis. With its visible-wavelength transparency, flexibility, broadband absorption, low profile, excellent angle stability and polarization insensitivity, the proposed absorber is highly favored for practical applications in microwave engineering, such as electromagnetic interference and stealth technology. Moreover, the proposed design method of topology optimization can be extended to design the absorber quickly and efficiently, according to specific engineering requirements.

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Topology Optimization Design of Integral Structure of Woodworking Machine Tool

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.37-38.1591 ◽

2010 ◽

Vol 37-38 ◽

pp. 1591-1594

Author(s):

Zhao Xin Meng ◽

Jun Cao ◽

Zhi Wei Li ◽

Jian Xin Zhao

Keyword(s):

Topology Optimization ◽

Machine Tool ◽

Objective Function ◽

Optimization Design ◽

Design Method ◽

Dynamic Properties ◽

Convergence Criteria ◽

Related Factors ◽

Economical Efficiency ◽

Integral Structure

In accordance with integral structure of woodworking machine tool (WMT), this paper uses the method based on topology optimization design to establish the objective function, constraints, and convergence Criteria. In the meantime, some related factors of woodworking machine tool (WMT), such as economical efficiency, stability, and dynamic properties are taken into consideration. Moreover, through analyzing an instance, the validity of design method has been demonstrated.

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Topology Optimization Design Method for Supporting Structures of Optical Reflective Mirrors Based on Zernike Coefficient Optimization Model

ACTA PHOTONICA SINICA ◽

10.3788/gzxb20204906.0622001 ◽

2020 ◽

Vol 49 (6) ◽

pp. 622001-622001

Author(s):

施胤成 Yin-cheng SHI ◽

闫怀德 Huai-de YAN ◽

宫鹏 Peng GONG ◽

刘韬 Tao LIU ◽

王强龙 Qiang-long WANG ◽

...

Keyword(s):

Topology Optimization ◽

Optimization Model ◽

Optimization Design ◽

Design Method ◽

Coefficient Optimization ◽

Supporting Structures

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Highly Transparent Broadband and Polarization-Insensitive Absorber Based on Metasurface

Applied Sciences ◽

10.3390/app10249125 ◽

2020 ◽

Vol 10 (24) ◽

pp. 9125

Author(s):

Houdi Xiao ◽

Ruiru Qin ◽

Mingyun Lv ◽

Chuanzhi Wang

Keyword(s):

Incidence Angle ◽

Wide Band ◽

Metamaterial Absorber ◽

Light Transmittance ◽

Cutoff Wavelength ◽

Broadband Absorption ◽

Low Profile ◽

Wide Range ◽

Potential Applications ◽

Polarization Insensitive

A highly transparent polarization-insensitive metamaterial absorber with wideband microwave absorption is presented. The broadband absorption (6.0~16.7 GHz, absorptance > 85%) is achieved using three patterned resistive metasurfaces. The visible light transmittance of the absorber is as high as 85.7%. The thickness of the absorber is 4.42 mm, which is only 0.088 times of the upper-cutoff wavelength. A prototype sample is fabricated and measured to demonstrate its excellent performance. The experimental results agree well with the simulation results. In view of its wide band absorption, high transmittance, low profile, polarization insensitivity and wide incidence angle stability, the presented absorber has a wide range of potential applications.

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Topology Optimization Design and Experimental Research of a 3D-Printed Metal Aerospace Bracket Considering Fatigue Performance

Applied Sciences ◽

10.3390/app11156671 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6671

Author(s):

Yisheng Chen ◽

Qianglong Wang ◽

Chong Wang ◽

Peng Gong ◽

Yincheng Shi ◽

...

Keyword(s):

Topology Optimization ◽

High Performance ◽

Optimization Design ◽

Fatigue Testing ◽

Design Method ◽

Vertical Direction ◽

Structure Design ◽

Fatigue Performance ◽

Original Structure ◽

Topology Optimization Problem

In the aerospace industry, spacecraft often serve in harsh operating environments, so the design of ultra-lightweight and high-performance structures is a major requirement in aerospace structure design. In this article, a lightweight aerospace bracket considering fatigue performance was designed by topology optimization and manufactured by 3D-printing. Considering the requirements of assembly with a fixture for fatigue testing and avoiding stress concentration, a reconstructed model was presented by CAD software before manufacturing. To improve the fatigue performance of the structure, this article proposes the design idea of abstracting the practiced working condition of the bracket subjected to cycle loads in the vertical direction via a multiple load-case topology optimization problem by minimizing compliance under a variety of asymmetric extreme loading conditions. Parameter sweeping was used to improve the computational efficiency. The mass of the new bracket was reduced by 37% compared to the original structure. Both numerical simulation and the fatigue test were implemented to support the validity of the new bracket. This work indicates that the integration of the proposed topology optimization design method and additive manufacturing can be a powerful tool for the design of lightweight structures considering fatigue performance.

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Performance Enhancement of Opened Resonance Photoacoustic Cells Based on Three Dimensional Topology Optimization

Photonics ◽

10.3390/photonics8090380 ◽

2021 ◽

Vol 8 (9) ◽

pp. 380

Author(s):

Zihao Tang ◽

Wenjun Ni ◽

Zehao Li ◽

Jin Hou ◽

Shaoping Chen ◽

...

Keyword(s):

Topology Optimization ◽

Performance Enhancement ◽

Three Dimensional ◽

High Sensitivity ◽

Wide Frequency Range ◽

Lower Threshold ◽

Optimization Approach ◽

The Finite Element Method ◽

Practical Applications ◽

Threshold Detection

Photoacoustic (PA) spectroscopy techniques enable the detection of trace substances. However, lower threshold detection requirements are increasingly common in practical applications. Thus, we propose a systematic geometry topology optimization approach on a PA cell to enhance the intensity of its detection signal. The model of topology optimization and pressure acoustics in the finite element method was exploited to construct a PA cell and then acquire the optimal structure. In the assessment, a thermo-acoustic model was constructed to properly simulate the frequency response over the range of 0–70 kHz and the temperature field distribution. The simulation results revealed that the acoustic gain of the optimized cell was 2.7 and 1.3 times higher than conventional cells near 25 and 52 kHz, respectively. Moreover, the optimized PA cell achieved a lower threshold detection over a wide frequency range. Ultimately, this study paves a new way for designing and optimizing the geometry of multifarious high-sensitivity PA sensors.

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Structural Topology Optimization for Improvements of some Shell Structures' Rib Design Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.385-386.1927 ◽

2013 ◽

Vol 385-386 ◽

pp. 1927-1932

Author(s):

Jian Xiang Sun ◽

Ye Yang ◽

Jing Yi Tian

Keyword(s):

Topology Optimization ◽

Shell Structure ◽

Optimization Design ◽

Fe Simulation ◽

Design Method ◽

Topological Optimization ◽

Optimal Topology ◽

Structural Topology ◽

Validity And Reliability ◽

The Continuum

In order to overcome the shortcoming of traditional mathematical model of topology optimization which aims to the continuum structures, a new implementation combined with TOSCA Structure software is presented. To examine the accuracy of optimal topology of this kind of structural, the programming scheme for the conceptual design of one shell structure using topological optimization approaches is set firstly, then build up a new topology optimization design method of the shell structure rib model. Through the FE simulation calculations from Project 1 to Project 4, different improvement results of maximum displacements are obtained. These results demonstrate the validity and reliability of the method.

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Topology Optimization of Multi-Materials Compliant Mechanisms

Applied Sciences ◽

10.3390/app11093828 ◽

2021 ◽

Vol 11 (9) ◽

pp. 3828

Author(s):

Wenjie Ge ◽

Xin Kou

Keyword(s):

Topology Optimization ◽

Elastic Modulus ◽

Optimization Design ◽

Compliant Mechanisms ◽

Compliant Mechanism ◽

Design Method ◽

Least Square ◽

Convergent Method ◽

Material Conditions ◽

Moving Asymptotes

In this article, a design method of multi-material compliant mechanism is studied. Material distribution with different elastic modulus is used to meet the rigid and flexible requirements of compliant mechanism at the same time. The solid isotropic material with penalization (SIMP) model is used to parameterize the design domain. The expressions for the stiffness matrix and equivalent elastic modulus under multi-material conditions are proposed. The least square error (LSE) between the deformed and target displacement of the control points is defined as the objective function, and the topology optimization design model of multi-material compliant mechanism is established. The oversaturation problem in the volume constraint is solved by pre-setting the priority of each material, and the globally convergent method of moving asymptotes (GCMMA) is used to solve the problem. Widely studied numerical examples are conducted, which demonstrate the effectiveness of the proposed method.

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