scholarly journals Optically Transparent Flexible Broadband Metamaterial Absorber Based on Topology Optimization Design

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1419
Author(s):  
Pingping Min ◽  
Zicheng Song ◽  
Lei Yang ◽  
Victor G. Ralchenko ◽  
Jiaqi Zhu

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.

2010 ◽  
Vol 37-38 ◽  
pp. 1591-1594
Author(s):  
Zhao Xin Meng ◽  
Jun Cao ◽  
Zhi Wei Li ◽  
Jian Xin Zhao

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.


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 ◽  
...  

2020 ◽  
Vol 10 (24) ◽  
pp. 9125
Author(s):  
Houdi Xiao ◽  
Ruiru Qin ◽  
Mingyun Lv ◽  
Chuanzhi Wang

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.


2021 ◽  
Vol 11 (15) ◽  
pp. 6671
Author(s):  
Yisheng Chen ◽  
Qianglong Wang ◽  
Chong Wang ◽  
Peng Gong ◽  
Yincheng Shi ◽  
...  

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.


Photonics ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 380
Author(s):  
Zihao Tang ◽  
Wenjun Ni ◽  
Zehao Li ◽  
Jin Hou ◽  
Shaoping Chen ◽  
...  

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.


2013 ◽  
Vol 385-386 ◽  
pp. 1927-1932
Author(s):  
Jian Xiang Sun ◽  
Ye Yang ◽  
Jing Yi Tian

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.


2021 ◽  
Vol 11 (9) ◽  
pp. 3828
Author(s):  
Wenjie Ge ◽  
Xin Kou

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.


2005 ◽  
Vol 42 (5) ◽  
pp. 1375-1375 ◽  
Author(s):  
Shinkyu Jeong ◽  
Mitsuhiro Murayama ◽  
Kazuomi Yamamoto

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