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

Photonics ◽  
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.

A Systematic Topology Optimization Approach for Optimal Stiffener Design

1998 ◽  
Author(s):  
Jian Hui Luo ◽  
Hae Chang Gea
Keyword(s):  
Topology Optimization ◽  
Location Problem ◽  
Eigenvalue Problems ◽  
Three Dimensional ◽  
Orthotropic Materials ◽  
Optimization Approach ◽  
Design Domain ◽  
Plate Structures ◽  
Shell Plate

Abstract A systematic topology optimization approach is developed to design the optimal stiffener of three dimensional shell/plate structures in static and eigenvalue problems. Optimal stiffener design involves the determination of the best location and orientation. In this paper, the stiffener location problem is solved by a microstructure-based design domain method and the orientation probelm is modeled as an optimal orientation problem of equivalent orthotropic materials, which is solved by a newly developed energy based method. Examples are presented to demonstrate the application of the proposed approach.

Three-Dimensional Electrical Impedance Tomography: A Topology Optimization Approach

2008 ◽  
Vol 55 (2) ◽  
pp. 531-540 ◽  
Author(s):  
LuÍs Augusto Motta Mello ◽  
CÍcero Ribeiro de Lima ◽  
Marcelo Britto Passos Amato ◽  
Raul Gonzalez Lima ◽  
EmÍlio Carlos Nelli Silva
Keyword(s):  
Topology Optimization ◽  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Three Dimensional ◽  
Optimization Approach ◽  
Impedance Tomography

Topology Optimization of Three-Dimensional Woven Materials Using a Ground Structure Design Variable Representation

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Seung-Hyun Ha ◽  
Hak Yong Lee ◽  
Kevin J. Hemker ◽  
James K. Guest
Keyword(s):  
Topology Optimization ◽  
Design Variable ◽  
Three Dimensional ◽  
Structure Design ◽  
Optimization Approach ◽  
Ground Structure ◽  
Flow Equations ◽  
Combined Algorithm ◽  
Variable Representation ◽  
3D Weaving

Three-dimensional (3D) weaving has recently arisen as viable means for manufacturing metallic, architected microlattices. Herein, we describe a topology optimization approach for designing the architecture of such 3D woven lattices. A ground structure design variable representation is combined with linear manufacturing constraints and a projection mapping to realize lattices that satisfy the rather restrictive topological constraints associated with 3D weaving. The approach is demonstrated in the context of inverse homogenization to design lattices with maximized fluid permeability. Stokes flow equations with no-slip conditions governing unit cell flow fields are interpolated using the Darcy–Stokes finite element model, leveraging existing work in the topology optimization of fluids. The combined algorithm is demonstrated to design manufacturable lattices with maximized permeability whose properties have been experimentally measured in other published work.

scholarly journals Performance Enhancement of the Location and Recognition of a Φ-OTDR System Using CEEMDAN-KL and AMNBP

2020 ◽  
Vol 10 (9) ◽  
pp. 3047
Author(s):  
Yanzhu Hu ◽  
Zhen Meng ◽  
Xinbo Ai ◽  
Yu Hu ◽  
Yixin Zhang ◽  
...  
Keyword(s):  
Performance Enhancement ◽  
Signal To Noise Ratio ◽  
Dead Zone ◽  
Recognition Rate ◽  
High Sensitivity ◽  
Ensemble Empirical Mode Decomposition ◽  
Time Domain Reflectometry ◽  
Long Distance ◽  
Practical Applications ◽  
Leibler Divergence

It is commonly known that for characteristics, such as long-distance, high-sensitivity, and full-scale monitoring, phase-sensitive optical time-domain reflectometry (Φ-OTDR) has developed rapidly in many fields, especially with the arrival of 5G. Nevertheless, there are still some problems obstructing the application for practical environments. First, the fading effect leads to some results falling into the dead zone, which cannot be demodulated effectively. Second, because of the high sensitivity, the Φ-OTDR system is easy to be interfered with by strong noise in practical environments. Third, the large volume of data caused by the fast responses require a lot of calculations. All the above problems hinder the performance of Φ-OTDR in practical applications. This paper proposes an integration method based on a complete ensemble empirical mode decomposition with adaptive noise and Kullback–Leibler divergence (CEEMDAN-KL) and an adaptive moving neighbor binary pattern (AMNBP) to enhance the performance of Φ-OTDR. CEEMDAN-KL improved the signal characteristics in low signal-to-noise ratio (SNR) conditions. AMNBP optimized the location and recognition via a high calculation efficiency. Experimental results show that the average recognition rate of four kinds of events reached 94.03% and the calculation efficiency increased by 20.0%, which show the excellent performance of Φ-OTDR regarding location and recognition in practical environments.

Crashworthiness Design Using Topology Optimization

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Neal M. Patel ◽  
Byung-Soo Kang ◽  
John E. Renaud ◽  
Andrés Tovar
Keyword(s):  
Topology Optimization ◽  
Design Space ◽  
Three Dimensional ◽  
Manufacturing Cost ◽  
Optimization Approach ◽  
Maximum Displacement ◽  
Efficient Manner ◽  
Response Surface Approximations ◽  
Cost Constraints ◽  
Crashworthiness Design

Crashworthiness design is an evolving discipline that combines vehicle crash simulation and design synthesis. The goal is to increase passenger safety subject to manufacturing cost constraints. The crashworthiness design process requires modeling of the complex interactions involved in a crash event. Current approaches utilize a parametrized optimization approach that requires response surface approximations of the design space. This is due to the expensive nature of numerical crash simulations and the high nonlinearity and noisiness in the design space. These methodologies usually require a significant effort to determine an initial design concept. In this paper, a heuristic approach to continuum-based topology optimization is developed for crashworthiness design. The methodology utilizes the cellular automata paradigm to generate three-dimensional design concepts. Furthermore, a constraint on maximum displacement is implemented to maintain a desired performance of the structures synthesized. Example design problems are used to demonstrate that the proposed methodology converges to a final topology in an efficient manner.

Innovative Structural Topology Optimization Approach for Rotordynamics Components Using Innovative Materials and New Manufacturing Techniques

2017 ◽  
Author(s):  
Enrico Boccini ◽  
Enrico Meli ◽  
Andrea Rindi ◽  
Simone Corbò ◽  
Giuseppe Iurisci
Keyword(s):  
Topology Optimization ◽  
Three Dimensional ◽  
Optimization Approach ◽  
Complex Structures ◽  
Concept Design ◽  
Structural Topology ◽  
Innovative Strategy ◽  
Innovative Materials ◽  
Manufacturing Techniques ◽  
Near Future

Topology optimization is an innovative strategy applied in the turbomachinery field with the aim of substantially improving the performances of turbomachinery components in terms of weights, stress levels and rotation speed, with a very remarkable economic impact. Being very flexible, topology optimization allows to manage the structures topology, significantly improving material distribution within a given design space for a given set of loads and boundary conditions. In this paper, the authors, in cooperation with General Electric Nuovo Pignone, develop a new concept design of a turbine disk and the optimized component is compared to the benchmark, in order to verify the achieved improvements. Special attention is paid to the use of innovative materials with lattice structures, characterized by complex three-dimensional geometries. Thanks to advanced technologies, as additive manufacturing, it is now possible to effectively exploit topology optimization to develop new components featured by complex structures. The developed prototypes will be manufactured and tested in the near future together with the industrial partners.

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
Keyword(s):  
Topology Optimization ◽  
Electromagnetic Interference ◽  
Optimization Design ◽  
Design Method ◽  
Optical Transmittance ◽  
Metamaterial Absorber ◽  
Wide Frequency Range ◽  
Practical Applications ◽  
Broadband Absorption ◽  
Low Profile

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.

scholarly journals Design of a Surface Plasmon Resonance Temperature Sensor with Multi-Wavebands Based on Conjoined-Tubular Anti-Resonance Fiber

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 231
Author(s):  
Qiming Wang ◽  
Xuenan Zhang ◽  
Xin Yan ◽  
Fang Wang ◽  
Tonglei Cheng
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Temperature Sensor ◽  
Structural Parameters ◽  
High Sensitivity ◽  
Biological Research ◽  
The Finite Element Method ◽  
Practical Applications ◽  
Spr Effect

In this work, a surface plasmon resonance (SPR) temperature sensor based on a con-joined-tubular anti-resonance optical fiber (CTF) was theoretically designed and analyzed using the finite element method. The CTF cladding was composed of eight pairs of conjoined tubes, and one or two holes of the tubes were selectively coated with gold to generate the SPR effect. Alcohol was injected into the core of the CTF to work as the sensing medium using vapor deposition. The proposed sensing structure exhibited excellent birefringence and produced more than six resonant peaks in different wavebands of the X and Y polarization. The positions of those resonant peaks were sensitive to temperature change, and the simulated sensitivity was about 3.2–3.6 nm/°C. The multiple working wavebands of the proposed sensing structure could be used for self-verification. Moreover, the influence of structural parameters on sensing performance was analyzed in detail. Possessing features of high sensitivity, good birefringence, multiple measuring wavebands, and self-verification, the proposed CTF-based SPR sensor has great potential in practical applications such as biological research and chemical sensing.

Design of Phononic Materials/Structures Using Toplogy Optimization

2006 ◽  
Author(s):  
Cory J. Rupp ◽  
Anton Evgrafov ◽  
Kurt Maute ◽  
Martin L. Dunn
Keyword(s):  
Thin Film ◽  
Topology Optimization ◽  
Surface Wave ◽  
Three Dimensional ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Optimization Approach ◽  
Feature Resolution ◽  
Wave Device

We develop a topology optimization approach to design two- and three-dimensional phononic materials/structures. Whereas most phononic crystals are based on ideas of periodicity, our approach relieves us of this constraint and allows for the creation of much more complex and efficient designs. It also enables us to go beyond simple filters and waveguides to the point of creating phononic devices. We focus on surface wave devices which carry the energy of the wave near and along the surface of the device. The design of surface wave devices is particularly attractive given recent advances in nano- and micro-manufacturing processes, such as thin-film deposition, etching, and lithography, which make it possible to precisely place thin film materials on a substrate with sub-micron feature resolution. The thin films can be made thick enough to affect most of the energy propagating in the surface wave and therefore a patterned thin film is all that is needed to create a surface wave device. It is the role of topology optimization to determine this pattern.

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