scholarly journals Numerical Design and Experimental Validation of a Plastic 3D-Printed Waveguide Antenna for Shallow Object Microwave Imaging

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Luca Bossi ◽  
Pierluigi Falorni ◽  
Saverio Priori ◽  
Roberto Olmi ◽  
Lorenzo Capineri
Keyword(s):  
3D Printing ◽  
Plastic Material ◽  
Signal To Noise Ratio ◽  
Microwave Imaging ◽  
Manufacturing Technology ◽  
Cylindrical Waveguide ◽  
Natural Soil ◽  
Scanning System ◽  
Relative Dielectric Permittivity ◽  
Buried Objects

AbstractMicrowave imaging of shallow buried objects has been demonstrated with holographic radar for landmine detection, civil engineering and cultural heritage. A key component of this system is the antenna based on a truncated cylindrical waveguide with two feeds. This paper investigates for the first time a manufacturing technology based on the 3D printing of a volumetric cylindrical plastic antenna. The investigation of this manufacturing technology was motivated by the reduction in the antenna size and customization of the electromagnetic characteristics to the radio frequency electronics mounted on the robotic scanning system. The antenna that was designed using a simulator and filled with polylactic acid plastic material (relative dielectric permittivity Ɛr = 2.5) is compared to the metal antenna, both operating at around 2 GHz. The goal was to replicate the characteristics of the void core antenna to be able to provide the same quality/information of the microwave images of shallow buried objects. Finally, we compared the scan results of dielectric and metal targets both in the air and in natural soil. From the observation of some of the characteristics of the images, such as dynamics, morphology of the target, signal-to-noise ratio, and operating distance, we demonstrate that 3D printing for volumetric cylindrical waveguide antenna could be used to obtain compact and easily adaptable antennas for different applications in remote sensing.

scholarly journals Designing of an original extruding system for 3D printing of parts made of plastic material in powder-state form

2021 ◽  
Vol 1009 ◽  
pp. 012043
Author(s):  
R Păcurar ◽  
S Pascu ◽  
A Păcurar ◽  
D S Stan ◽  
E Teuţan ◽  
...  
Keyword(s):  
3D Printing ◽  
Plastic Material ◽  
State Form

scholarly journals Use of 3D printing for learning science and manufacturing technology

2021 ◽  
Author(s):  
Basuki Wibawa ◽  
Halimatus Syakdiyah ◽  
Jenny S. Siregar ◽  
D. A. Asrorie
Keyword(s):  
3D Printing ◽  
Manufacturing Technology ◽  
Learning Science

Manufacture of Lenses and Diffraction Gratings Using DLP As an Additive Manufacturing Technology

2018 ◽  
Author(s):  
Laura Daniela Vallejo Melgarejo ◽  
Jose García ◽  
Ronald G. Reifenberger ◽  
Brittany Newell
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Diffraction Grating ◽  
Diffraction Gratings ◽  
Optical Microscope ◽  
Manufacturing Technology ◽  
Manufacturing Processes ◽  
Digital Light Processing ◽  
Additive Manufacturing Technology ◽  
Potential Use

This document condenses the results obtained when 3D printing lenses and their potential use as diffraction gratings using Digital Light Processing (DLP), as an additive manufacturing technique. This project investigated the feasibility of using DLP additive manufacturing for producing custom designed lenses and gratings. DLP was identified as the preferred manufacturing technology for gratings fabrication. Diffraction gratings take advantage of the anisotropy, inherent in additive manufacturing processes, to produce a collated pattern of multiple fringes on a substrate with completely smooth surfaces. The gratings are transmissive and were manufactured with slit separations of 10, 25 and 50 μm. More than 50 samples were printed at various build angles and mechanically treated for maximum optical transparency. The variables of the irradiance equation were obtained from photographs taken with an optical microscope. These values were used to estimate theoretical irradiance patterns of a diffraction grating and compared against the experimental 3-D printed grating. The resulting patterns were found to be remarkably similar in amplitude and distance between peaks when compared to theoretical values.

Performance Oriented Design of Semiregular Anisotropic Porous Structures

2018 ◽  
Author(s):  
Chao Xu ◽  
Lili Pan ◽  
Ming Li ◽  
Shuming Gao
Keyword(s):  
3D Printing ◽  
Porous Materials ◽  
Design Problem ◽  
Degrees Of Freedom ◽  
Design Space ◽  
Manufacturing Technology ◽  
Porous Structures ◽  
Precise Control ◽  
And Performance

Porous materials / structures have wide applications in industry, since the sizes, shapes and positions of their pores can be adjusted on various demands. However, the precise control and performance oriented design of porous structures are still urgent and challenging, especially when the manufacturing technology is well developed due to 3D printing. In this study, the control and design of anisotropic porous structures are studied with more degrees of freedom than isotropic structures, and can achieve more complex mechanical goals. The proposed approach introduces Super Formula to represent the structural cells, maps the design problem to an optimal problem using PGD, and solves the optimal problem using MMA to obtain the structure with desired performance. The proposed approach is also tested on the performance of the expansion of design space, the capture of the physical orientation and so on.

scholarly journals Additive Manufacturing in Vascular Stent Fabrication

2019 ◽  
Vol 253 ◽  
pp. 03003
Author(s):  
Lei Yang ◽  
Xin Chen ◽  
Lei Zhang ◽  
Lei Li ◽  
Shuangzhu Kang ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Personalized Medicine ◽  
High Efficiency ◽  
Structural Characteristics ◽  
Manufacturing Technology ◽  
Vascular Stent ◽  
Additive Manufacturing Technology ◽  
Vascular Scaffolds ◽  
And Personalized Medicine

High-efficiency formation of personalized stent by additive manufacturing (3D printing) has gained deal of attention and research in interventional and personalized medicine. In this article, the structural characteristics of vascular scaffolds and the application and innovation of additive manufacturing technology in the process of angioplasty are reviewed. In the future, with the continuous maturity of additive manufacturing technology, it is expected to be an important part of interventional precision medicine to manufacture personalized vascular stent.

Influence of a localized plastic layer on embankment stability

1977 ◽  
Vol 14 (4) ◽  
pp. 524-530 ◽  
Author(s):  
C. D. Thompson ◽  
J. J. Emery
Keyword(s):  
Finite Element ◽  
Stability Analysis ◽  
Clayey Soil ◽  
Plastic Material ◽  
Plastic Layer ◽  
Natural Soil ◽  
General Terms ◽  
Clayey Silt ◽  
The Stability ◽  
Embankment Stability

Conventional stability analyses of a 47 ft (14.3 m) high embankment constructed of clayey silt fill indicated a satisfactory design with 2:1 slopes. However, cracking of the fill and movements of the embankment occurred when its height reached 32 ft (9.8 m). Investigation revealed that, in general terms, the geotechnical profile employed for the stability analysis was satisfactory. There was a localized layer of firm clayey soil at the interface between the fill and natural soil, which coincided with the observed cracks and the zone of high pore pressure.Construction scheduling was critical, and an initial wedge analysis showed that a 17 ft (5.2 m) high berm would ensure adequate safety during completion of the fill. A detailed investigation followed to determine the actual deformation mechanism responsible for the cracking. This included plane strain finite element runs using estimated moduli values. It was concluded that the cracking was caused by ‘spreading’ of plastic material at or near the base of the embankment. This case history illustrates that localized layers of weaker soil can be critical even when construction has been carefully controlled.

scholarly journals Bone-inspired 3D printed structures for construction applications

2019 ◽  
Vol 14 (1) ◽  
pp. 111-124
Author(s):  
Roberto Naboni ◽  
Anja Kunic
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Computational Design ◽  
Bone Microstructure ◽  
Manufacturing Technology ◽  
Support Design ◽  
Efficient Construction ◽  
3D Printed ◽  
Viable Approach ◽  
Tectonic System

Overconsumption of resources is one of the greatest challenges of our century. The amount of material that is being extracted, harvested and consumed in the last decades is increasing tremendously. Building with new manufacturing technology, such as 3D Printing, is offering new perspectives in the way material is utilized sustainably within a construction. This paper describes a study on how to use Additive Manufacturing to support design logics inspired by the bone microstructure, in order to build materially efficient architecture. A process which entangles computational design methods, testing of 3D printed specimens, developments of prototypes is described. A cellular-based tectonic system with the capacity to vary and adapt to different loading conditions is presented as a viable approach to a material-efficient construction with Additive Manufacturing.

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