Four-Dimensional Printing for Freeform Surfaces: Design Optimization of Origami and Kirigami Structures

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Tsz-Ho Kwok ◽  
Charlie C. L. Wang ◽  
Dongping Deng ◽  
Yunbo Zhang ◽  
Yong Chen
Keyword(s):  
Shape Optimization ◽  
Three Dimensional ◽  
Optimization Method ◽  
Two Dimensional ◽  
3D Shape ◽  
Optimization Framework ◽  
Interior Boundary ◽  
Folding Structure ◽  
Dimensional Printing ◽  
3D Surfaces

A self-folding structure fabricated by additive manufacturing (AM) can be automatically folded into a demanding three-dimensional (3D) shape by actuation mechanisms such as heating. However, 3D surfaces can only be fabricated by self-folding structures when they are flattenable. Most generally, designed parts are not flattenable. To address the problem, we develop a shape optimization method to modify a nonflattenable surface into flattenable. The shape optimization framework is equipped with topological operators for adding interior/boundary cuts to further improve the flattenability. When inserting cuts, self-intersection is locally prevented on the flattened two-dimensional (2D) pieces. The total length of inserted cuts is also minimized to reduce artifacts on the finally folded 3D shape.

General, Vertical, Three-Dimensional Printing of Two-Dimensional Materials with Multiscale Alignment

ACS Nano ◽  
2019 ◽  
Vol 13 (11) ◽  
pp. 12653-12661 ◽  
Author(s):  
Zhiqiang Liang ◽  
Yong Pei ◽  
Chaoji Chen ◽  
Bo Jiang ◽  
Yonggang Yao ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Two Dimensional ◽  
Three Dimensional Printing ◽  
Two Dimensional Materials ◽  
Dimensional Printing

scholarly journals Deconstructing double-barred galaxies in 2D and 3D – II. Two distinct groups of inner bars

2020 ◽  
Vol 494 (2) ◽  
pp. 1826-1837 ◽  
Author(s):  
A de Lorenzo-Cáceres ◽  
J Méndez-Abreu ◽  
B Thorne ◽  
L Costantin
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Length Ratio ◽  
Host Galaxy ◽  
Two Dimensional ◽  
Slow Process ◽  
Photometric Analysis ◽  
Barred Galaxies ◽  
3D Shape ◽  
2D And 3D

ABSTRACT The intrinsic photometric properties of inner and outer stellar bars within 17 double-barred galaxies are thoroughly studied through a photometric analysis consisting of (i) two-dimensional (2D) multicomponent photometric decompositions, and (ii) three-dimensional (3D) statistical deprojections for measuring the thickening of bars, thus retrieving their 3D shape. The results are compared with previous measurements obtained with the widely used analysis of integrated light. Large-scale bars in single- and double-barred systems show similar sizes, and inner bars may be longer than outer bars in different galaxies. We find two distinct groups of inner bars attending to their in-plane length and ellipticity, resulting in a bimodal behaviour for the inner/outer bar length ratio. Such bimodality is related neither to the properties of the host galaxy nor the dominant bulge, and it does not show a counterpart in the dimension off the disc plane. The group of long inner bars lays at the lower end of the outer bar length versus ellipticity correlation, whereas the short inner bars are out of that relation. We suggest that this behaviour could be due to either a different nature of the inner discs from which the inner bars are dynamically formed or a different assembly stage for the inner bars. This last possibility would imply that the dynamical assembly of inner bars is a slow process taking several Gyr to happen. We have also explored whether all large-scale bars are prone to develop an inner bar at some stage of their lives, possibility we cannot fully confirm or discard.

scholarly journals Development of a computer-aided engineering–supported process for the manufacturing of customized orthopaedic devices by three-dimensional printing onto textile surfaces

2020 ◽  
Vol 15 ◽  
pp. 155892502091762
Author(s):  
Dustin Ahrendt ◽  
Arturo Romero Karam
Keyword(s):  
Three Dimensional ◽  
Computer Aided Engineering ◽  
Two Dimensional ◽  
Three Dimensional Printing ◽  
Textile Materials ◽  
Fused Deposition ◽  
Custom Made ◽  
Computer Aided ◽  
Dimensional Printing ◽  
Textile Fabric

Today, additive manufacturing, also called three-dimensional printing, is used for producing prototypes as well as other products for various industrial sectors. Although this technology is already well established in the automotive, aviation and space travel, building, dental and medical sectors, its integration in the textile and ready-made industry is still in progress. At present, there is a lack of specific application scenarios for the combination of three-dimensional printing and textile materials, apart from fashion and shoe design. Hence, this article presents a digital computer-aided engineering–supported process to manufacture customized orthopaedic devices by three-dimensional printing directly onto a textile fabric. State-of-the-art fabrication methods for orthoses are typically labour intensive. The combination of three-dimensional scanning, computer-aided design modelling and three-dimensional printing onto textile materials open up new possibilities for producing custom-made products. After three-dimensional scanning of a patient’s individual body shape, the surface is prepared for constructing the textile pattern cuts by reverse engineering. The transformation of the designed three-dimensional patterns into two-dimensional is software supported. Additional positioning lines in accordance with specific body measurements are transferred onto the two-dimensional pattern cuts, which are then used as the basis for the design of the three-dimensional printed functional elements. Subsequently, the design is saved in STL (Standard Triangulation/Tessellation Language) file format, prepared by slicing and directly printed onto textile pattern cuts by means of fused deposition modelling. The last manufacturing step involves the assembly of the textile fabric. The proposed process is demonstrated by an example application scenario, thus proving its potential for industrial use in the textile and ready-made industry.

Three-Dimensional Configuration in the Graphic Design

2014 ◽  
Vol 484-485 ◽  
pp. 1110-1113
Author(s):  
Yi Xiang Xu
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Modern World ◽  
Two Dimensional ◽  
Actual Situation ◽  
Book Design ◽  
3D Shape ◽  
Design Concepts ◽  
Space Design ◽  
Three Dimensional Configuration

The modern world is a stereo world dominated by the three-dimensional space. For a designer, the traditional plane design technique which is the design and arrangement relying solely on the graphics, texts, colors and other elements in the two-dimensional space has been unable to meet the needs of the people. A modern designers relying only on the means of expression of the two-dimensional space design has been unable to meet the current needs of practical design, and also cannot perfectly convey his unique design concepts. In this paper, by referring to a large number of related literatures, combined with the actual situation in the field of design, through comparison and investigation of a variety of methods, based on the specific concepts of the 3D shape, and combined with the thinking the actual situation of its emergence and development, the author summarizes the theoretical foundation of this new design concept. Mainly for the packaging design, book design, advertising design, the author ironically shows the practical application of 3D shape, and clearly shows the unique advantages compared with the traditional 2D design. Of course, compared with the traditional, the newly developing also has some inevitable defects.

scholarly journals 2D and 3D Shape Sensing Based on 7-Core Fiber Bragg Gratings

2020 ◽  
Vol 10 (4) ◽  
pp. 306-315
Author(s):  
Tianting Lai ◽  
Pu Cheng ◽  
Congliao Yan ◽  
Chi Li ◽  
Wenbin Hu ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Fiber Bragg Gratings ◽  
Bragg Gratings ◽  
Shape Reconstruction ◽  
Two Dimensional ◽  
3D Shape ◽  
3D Space ◽  
Core Fiber ◽  
Shape Sensing ◽  
2D And 3D

Abstract A fiber-optic shape sensing based on 7-core fiber Bragg gratings (FBGs) is proposed and experimentally demonstrated. The investigations are presented for two-dimensional and three-dimensional shape reconstruction by distinguishing bending and twisting of 7-core optical fiber with FBGs. The curvature and bending orientation can be calculated by acquiring FBG wavelengths from any two side cores among the six outer cores. And the shape sensing in three-dimensional (3D) space is computed by analytic geometry theory. The experiments corresponding of two-dimensional (2D) and 3D shape sensing are demonstrated and conducted to verify the theoretical principles. The resolution of curvature is about 0.1m−1 for 2D measuring. The error of angle in shape reconstruction is about 1.89° for 3D measuring. The proposed sensing technique based on 7-core FBGs is promising of high feasibility, stability, and repeatability, especially for the distinguishing ability on the bending orientation due to the six symmetrical cores on the cross-section.

Numerical Analysis of Nozzle and Afterbody Flow of Hypersonic Transport Systems

1995 ◽  
Vol 117 (3) ◽  
pp. 389-393
Author(s):  
T. Esch ◽  
M. Giehrl
Keyword(s):  
Three Dimensional ◽  
Exhaust System ◽  
Optimization Method ◽  
Operating Conditions ◽  
Transport Systems ◽  
Navier Stokes ◽  
Nozzle Flow ◽  
Two Dimensional ◽  
Direct Optimization ◽  
Hypersonic Aircraft

Using an implicit Finite-Volume Navier–Stokes code, the flow field in a Single Expansion Ramp Nozzle (SERN) for a hypersonic aircraft is studied. Comparisons between experimental data and CFD calculations for certain components of the integrated exhaust system (cold two-dimensional nozzle flow, high temperature reacting three-dimensional combustion chamber flow, and two-dimensional nozzle flow with external flow) are presented. To show the sensitivity of the considered components to off-design operating conditions, comprehensive numerical studies have been carried out. For the determination of nozzle performance a detailed two-dimensional analysis from transonic to hypersonic flight Mach numbers has been performed. A direct optimization method has been used to investigate the influence of the lower nozzle flap shape on the thrust vector.

scholarly journals Multi-Point Shape Optimization of a Horizontal Axis Tidal Stream Turbine

Eng ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 340-355
Author(s):  
Hassan el Sheshtawy ◽  
Ould el Moctar ◽  
Satish Natarajan
Keyword(s):  
Genetic Algorithm ◽  
Shape Optimization ◽  
Pressure Coefficient ◽  
Three Dimensional ◽  
Panel Method ◽  
Two Dimensional ◽  
Nsga Ii ◽  
Multi Objective Genetic Algorithm ◽  
Tidal Stream ◽  
Tidal Stream Turbine

A method was developed to perform shape optimization of a tidal stream turbine hydrofoil using a multi-objective genetic algorithm. A bezier curve parameterized the reference hydrofoil profile NACA 63815. Shape optimization of this hydrofoil maximized its lift-to-drag ratio and minimized its pressure coefficient, thereby increasing the turbines power output power and improving its cavitation characteristics. The Elitist Non-dominated Sorting Genetic Algorithm (NSGA-II) was employed to perform the shape optimization. A comparative study of two- and three-dimensional optimizations was carried out. The effect of varying the angle of attack on the quality of optimized results was also studied. Predictions based on two-dimensional panel method results were also studied. Predictions based on a two-dimensional panel method and on a computational fluid dynamics code were compared to experimental measurements.

Origami-Based Self-Folding Structure Design and Fabrication Using Projection Based Stereolithography

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Dongping Deng ◽  
Yong Chen
Keyword(s):  
3D Structure ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Middle Layer ◽  
Structure Design ◽  
The Self ◽  
Two Dimensional ◽  
Polystyrene Film ◽  
Folding Structure ◽  
Unique Capability

Self-folding structures have unique capability such as reconfiguration during their usage. Such capability can be beneficial for a wide variety of applications including biomedical and electronics products. In this paper, a novel fabrication approach based on a three-dimensional (3D) printing process is presented for fabricating self-folding structures that can be actuated in a heating environment. The thermo-actuating structures that are designed and fabricated by our method are two-dimensional (2D) origami sheets, which have multiple printed layers. The middle layer of an origami sheet is a prestrained polystyrene film with large shrinkage ratios when heated. Both its top and bottom surfaces are covered with cured resin that is printed in designed shapes. A foldable hinge is achieved by constraining the shrinkage of the film on one side while allowing the shrinkage of the film on another side when the origami sheet is exposed to a heating environment. Heuristic models of hinge's folding angles are developed based on the related folding mechanism. A 2D origami sheet design and fabrication method is presented for a given 3D structure. Various experimental tests are performed to verify the self-folding performance of the designed and fabricated origami sheets. Techniques on improving folding angle control are also discussed with possible applications.

Comparison of Plaster Casting with Three-Dimensional Cranial Imaging

2005 ◽  
Vol 42 (2) ◽  
pp. 157-164 ◽  
Author(s):  
Timothy R. Littlefield ◽  
Jennifer C. Cherney ◽  
Jerry N. Luisi ◽  
Stephen P. Beals ◽  
Kevin M. Kelly ◽  
...  
Keyword(s):  
Excellent Agreement ◽  
Imaging System ◽  
Three Dimensional ◽  
3D Models ◽  
Two Dimensional ◽  
Casting Technique ◽  
Equivalent Models ◽  
Plaster Casting ◽  
The Mean ◽  
3D Surfaces

Objective The development of a new cranial imaging system to capture a three-dimensional (3D) model of an infant's head has been previously reported. The accuracy of this new system has been independently established. However, before replacing the traditional plaster casting technique, the two methods require a comparison to ensure that the models they produce are equivalent. Methods Ten sequential infants were digitized by the 3D imaging system and the plaster casting technique following previously reported protocols. The cast models were also digitized so they could be compared with the digitized images. The two models (3dImage and Cast) were then imported into dimensional analysis software and aligned and registered with well-established registration algorithms. Difference maps that identified the variation between the two surfaces were generated for each pair, and descriptive statistics of these differences were recorded. Results The mean difference between the cast and the digitized models was 0.052 mm (standard deviation = 0.988), with a root mean square (RMS) difference of 1.028 mm. Two-dimensional slices obtained from the registered 3D surfaces demonstrated excellent agreement between the cranial contours. Conclusions In this investigation, the 3D models created by the new imaging system were found to be within 1.0 mm RMS of the models created by the plaster casting technique. Two-dimensional cranial contours demonstrated excellent agreement between the two methods. The results of this investigation confirmed that the new cranial imaging system and the traditional plaster casting technique yield equivalent models.

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