scholarly journals Design, Fabrication, and Testing of Active Skin Antenna with 3D Printing Array Framework

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Jinzhu Zhou ◽  
Haitao Li ◽  
Le Kang ◽  
Baofu Tang ◽  
Jin Huang ◽  
...  
Keyword(s):  
3D Printing ◽  
Microstrip Antenna ◽  
High Speed ◽  
Experimental Testing ◽  
Bayesian Optimization ◽  
Load Bearing ◽  
Manufacturing Method ◽  
Structural Surface ◽  
Control Circuits ◽  
Smart Skin

An active skin antenna with structural load-bearing and electromagnetic functions is usually installed in the structural surface of mobile vehicles such as aircrafts, warships, and high-speed train. This paper presents the design, fabrication, and testing of a novel active skin antenna which consists of an encapsulation shell, antenna skin, and RF and beam control circuits. The antenna skin which consists of the facesheet, honeycomb, array framework, and microstrip antenna elements was designed by using Bayesian optimization, in order to improve the design efficiency. An active skin antenna prototype with 32 microstrip antenna elements was fabricated by using a hybrid manufacturing method. In this method, 3D printing technology was applied to fabricate the array framework, and the different layers were bonded to form the final antenna skin by using traditional composite process. Some experimental testing was conducted, and the testing results validate the feasibility the proposed antenna skin structure. The proposed design and fabrication technique is suitable for the development of conformal load-bearing antenna or smart skin antenna installed in the structural surface of aircraft, warships, and armored vehicles.

scholarly journals Experimental Investigation of Fluid-Particle Interaction in Binder Jet 3D Printing

2021 ◽  
Author(s):  
Joshua J. Wagner ◽  
Hang Shu ◽  
Rahul Kilambi
Keyword(s):  
3D Printing ◽  
High Speed ◽  
Capillary Flow ◽  
Experimental Testing ◽  
Particle Interaction ◽  
Fluid Particle ◽  
Short Time Scale ◽  
Energy Applications ◽  
And Performance ◽  
Critical Components

Wide-scale adoption of binder jet 3D printing for mission-critical components in aerospace, biomedical, defense, and energy applications requires improvement in mechanical properties and performance characteristics of end-use components. Increased fidelity may be achieved with better understanding of the interfacial physics and complex fluid-particle interactions fundamental to the process. In this work, an experimental testing apparatus and procedure is developed to investigate the fluid and particle dynamics occurring upon impact of jetted binder droplets onto a powder bed. High-speed, microscopic imaging is employed to capture short time-scale phenomena such as ballistic particle ejection, capillary flow, and particle clustering. The effects of different process parameters (e.g., translational printhead velocity, jetting frequency, and impact velocity) on the dynamics of Inconel powder are studied. These experiments reveal that the fluid-particle interaction is significantly affected by a combination of printing parameters, ultimately governing the quality and performance of binder jet 3D printed components.

scholarly journals Multi-fidelity black-box optimization for time-optimal quadrotor maneuvers

2021 ◽  
pp. 027836492110333
Author(s):  
Gilhyun Ryou ◽  
Ezra Tal ◽  
Sertac Karaman
Keyword(s):  
Real World ◽  
High Speed ◽  
Analytical Approximation ◽  
Black Box ◽  
Bayesian Optimization ◽  
Optimization Framework ◽  
Quadrotor Aircraft ◽  
Time Optimal ◽  
Feasibility Constraints ◽  
Generation Problem

We consider the problem of generating a time-optimal quadrotor trajectory for highly maneuverable vehicles, such as quadrotor aircraft. The problem is challenging because the optimal trajectory is located on the boundary of the set of dynamically feasible trajectories. This boundary is hard to model as it involves limitations of the entire system, including complex aerodynamic and electromechanical phenomena, in agile high-speed flight. In this work, we propose a multi-fidelity Bayesian optimization framework that models the feasibility constraints based on analytical approximation, numerical simulation, and real-world flight experiments. By combining evaluations at different fidelities, trajectory time is optimized while the number of costly flight experiments is kept to a minimum. The algorithm is thoroughly evaluated for the trajectory generation problem in two different scenarios: (1) connecting predetermined waypoints; (2) planning in obstacle-rich environments. For each scenario, we conduct both simulation and real-world flight experiments at speeds up to 11 m/s. Resulting trajectories were found to be significantly faster than those obtained through minimum-snap trajectory planning.

scholarly journals High-Speed 3D Printing of High-Performance Thermosetting Polymers via Two-Stage Curing

2018 ◽  
Vol 39 (7) ◽  
pp. 1700809 ◽  
Author(s):  
Xiao Kuang ◽  
Zeang Zhao ◽  
Kaijuan Chen ◽  
Daining Fang ◽  
Guozheng Kang ◽  
...  
Keyword(s):  
3D Printing ◽  
High Speed ◽  
High Performance ◽  
Two Stage ◽  
Thermosetting Polymers

A Research for Angle Optimization of the SRM Used in Electric Actuator of Valves

2013 ◽  
Vol 404 ◽  
pp. 586-591
Author(s):  
Ding Hong Yang Yang ◽  
Dean Zhao ◽  
Ying Xin Jiang
Keyword(s):  
High Speed ◽  
Position Control ◽  
Experimental Testing ◽  
Optimal Switching ◽  
Switched Reluctance ◽  
Electric Actuator ◽  
Turn On ◽  
Reluctance Motor ◽  
Two Parameters ◽  
Theory Research

This paper uses TMS320F28335 DSP and MAX3032S CPLD as the controller of the 6/4 pole switched reluctance motor (SRM), and controls the motor by the method of current chopping control (CCC) in low speed and the method of angle position control (APC) in high speed. About the optimization of turn-on angle and turn-off angle when SRM is controlled by the method of APC, this paper discusses the optimal design of the two parameters by ways of theory research, simulation and experimental testing. The results show optimal switching angle can make speeded-up of the motor better and improve the performance of SRM.

scholarly journals High-Speed 3D Printing of Millimeter-Size Customized Aspheric Imaging Lenses with Sub 7 nm Surface Roughness

2018 ◽  
Vol 30 (18) ◽  
pp. 1705683 ◽  
Author(s):  
Xiangfan Chen ◽  
Wenzhong Liu ◽  
Biqin Dong ◽  
Jongwoo Lee ◽  
Henry Oliver T. Ware ◽  
...  
Keyword(s):  
Surface Roughness ◽  
3D Printing ◽  
High Speed

Research of the Load Bearing Capacity of Shape-Optimized Metal Inserts Embedded in CFRP under Different Types of Stresses

2017 ◽  
Vol 742 ◽  
pp. 636-643 ◽  
Author(s):  
Florentin Pottmeyer ◽  
Markus Muth ◽  
Kay André Weidenmann
Keyword(s):  
Bearing Capacity ◽  
Residual Strength ◽  
High Speed ◽  
Systematic Research ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Temperature Cycles ◽  
Pull Out ◽  
Different Types ◽  
Impact Energies

An efficient implementation of lightweight design is the use of continuous carbon fiber reinforced plastics (CFRP) due to their outstanding specific mechanical properties. Embedded metal elements, so-called inserts, can be used to join metal-based attachments to structural CFRP parts in the context of multi-material design. They differ from other mechanical fasteners and have distinctive benefits. In particular, drilling of the components to be joined can be avoided and, depending on the preforming, fiber continuity can be maintained using such elements. Thus, no local bearing stress is anticipated. Previous work published by the authors [1] dealt with a systematic research of the influence of different types of stresses on the load bearing capacity of welded inserts. This contribution aims at the investigation of the performance of shape-optimized inserts under the same types of loading to compare with the results of the welded inserts serving as a reference. For that purpose, the respective load bearing capacities were evaluated after preinduced damages from impact tests and thermal cycling. In addition, dynamic high-speed tensile tests (pull-out) were conducted under different loading velocities. It is shown that the load bearing capacities increased up to 19% for high velocities (250 mm/s) in comparison to quasi-static loading conditions (1.5 mm/min) showing an obvious strain rate dependency of the CFRP. Quasi-static residual strength measurements under tensile loading identified the influence of the respective preinduced damages of the insert. Influence of the thermal loading condition was evaluated by placing the specimens in a climate chamber and exposing it to various numbers of temperature cycles from-40 °C to +80 °C with a duration time of 1.5 hours each. Here, it turned out that already 10 temperature cycles decreased the quasi-static load bearing capacity up to 31%. According to DIN EN 6038 the specimens were loaded with different impact energies and the residual strength were measured carrying out pull-out tests. It could be shown that the damage tolerance is significantly lower for the shape-optimized insert due to failure-critical delamination. The optimized insert also endured lower impact energies and the influence on the performance was higher.

scholarly journals 3D printing technologies for creating models and nozzles in an aerodynamic shock tunnel experiment

2021 ◽  
Vol 2103 (1) ◽  
pp. 012033
Author(s):  
M A Kotov ◽  
N A Monakhov ◽  
S A Poniaev ◽  
P A Popov ◽  
K V Tverdokhlebov
Keyword(s):  
3D Printing ◽  
High Speed ◽  
Additive Technologies ◽  
Structure And Properties ◽  
Dynamic Experiment ◽  
Advantages And Disadvantages ◽  
Nozzle Block ◽  
Rapid Prototyping And Manufacturing ◽  
Manufacturing Techniques ◽  
Traditional Manufacturing

Abstract The features of 3D printing method for rapid prototyping and manufacturing of models for a pulsed high-speed gas-dynamic experiment are considered. Modern additive technologies allow the production of models. The basic properties of the materials and the advantages of 3D printing methods are described. The structure and properties of the obtained models can be unattainable using traditional manufacturing techniques. The design of the wind tunnel nozzle block is considered, which provides for the production of profiled contours using 3D printing. The advantages and disadvantages of use of such units on the shock tube are considered.

Thermoplastic 3D Printing-An Additive Manufacturing Method for Producing Dense Ceramics

2014 ◽  
Vol 12 (1) ◽  
pp. 26-31 ◽  
Author(s):  
Uwe Scheithauer ◽  
Eric Schwarzer ◽  
Hans-Jürgen Richter ◽  
Tassilo Moritz
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Manufacturing Method

scholarly journals Current Status and Prospects of Polymer Powder 3D Printing Technologies

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2406 ◽  
Author(s):  
Yue Wang ◽  
Zhiyao Xu ◽  
Dingdi Wu ◽  
Jiaming Bai
Keyword(s):  
3D Printing ◽  
High Speed ◽  
Selective Laser Sintering ◽  
Advanced Technology ◽  
Current Status ◽  
Utilization Rate ◽  
Process Selection ◽  
Forming Mechanism ◽  
Polymer Powder ◽  
Industry Applications

3D printing technology, which greatly simplifies the manufacturing of complex parts by a two-dimensional layer-upon-layer process, has flourished in recent years. As one of the most advanced technology, polymer powder 3D printing has many advantages such as high materials utilization rate, free of support structure, great design freedom, and large available materials, which has shown great potential and prospects in various industry applications. With the launch of the Multi jet Fusion system from HP, polymer powder 3D printing has been attracting more attention from industries and researchers. In this work, a comprehensive review of the main polymer powder-based 3D printing methods including binder jetting, selective laser sintering, high-speed sintering were carried out. Their forming mechanism, advantages and drawbacks, materials, and developments were presented, compared, and discussed respectively. In addition, this paper also gives suggestions on the process selection by comparing typical equipment parameters and features of each technology.

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