scholarly journals Simulation Informed CAD for 3D Nanoprinting

Micromachines ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 8 ◽  
Author(s):  
Jason D. Fowlkes ◽  
Robert Winkler ◽  
Eva Mutunga ◽  
Philip D. Rack ◽  
Harald Plank
Keyword(s):  
Analytical Model ◽  
Computer Aided Design ◽  
Critical Mass ◽  
Three Dimensional ◽  
Three Dimensional Objects ◽  
Non Linear ◽  
Out Of Plane ◽  
Digital Scanning ◽  
Definition Of ◽  
Bending Nanowires

A promising 3D nanoprinting method, used to deposit nanoscale mesh style objects, is prone to non-linear distortions which limits the complexity and variety of deposit geometries. The method, focused electron beam-induced deposition (FEBID), uses a nanoscale electron probe for continuous dissociation of surface adsorbed precursor molecules which drives highly localized deposition. Three dimensional objects are deposited using a 2D digital scanning pattern—the digital beam speed controls deposition into the third, or out-of-plane dimension. Multiple computer-aided design (CAD) programs exist for FEBID mesh object definition but rely on the definition of nodes and interconnecting linear nanowires. Thus, a method is needed to prevent non-linear/bending nanowires for accurate geometric synthesis. An analytical model is derived based on simulation results, calibrated using real experiments, to ensure linear nanowire deposition to compensate for implicit beam heating that takes place during FEBID. The model subsequently compensates and informs the exposure file containing the pixel-by-pixel scanning instructions, ensuring nanowire linearity by appropriately adjusting the patterning beam speeds. The derivation of the model is presented, based on a critical mass balance revealed by simulations and the strategy used to integrate the physics-based analytical model into an existing 3D nanoprinting CAD program is overviewed.

CAD Software for Cable Design: A Three-Dimensional Visualization Tool

2010 ◽  
Author(s):  
Rodrigo Provasi ◽  
Christiano Odir Cardoso Meirelles ◽  
Clo´vis de Arruda Martins
Keyword(s):  
Computer Aided Design ◽  
Structural Characteristics ◽  
Three Dimensional ◽  
Axial Stiffness ◽  
General Description ◽  
Post Processing ◽  
Cad System ◽  
Processing Resources ◽  
Definition Of ◽  
Electrical Cables

The concept and project of umbilical cables and flexible pipes are not simple tasks, due to the great variety of components and possible arrangements. The design of those elements is based on the functions they are intended to perform. Also, some structural characteristics determine which component will be selected, including electrical cables and hydraulic hoses, to control underwater equipment, protective sheaths, helically wounded tensile armors, anti-wear layers, interlocked carcasses; pressure armors and so on. The modeling process consists on defining the cable features and selecting the elements that will compose it. The process should take into account the desired structural characteristics, such as axial stiffness, and must respect some constraints, such as weight. To have an operational cable, one must follow a number of steps from definition to validation of the cable and any tool that provides a easier way to deal with this process is highly desired. In this scenario, Computer Aided Design software was conceived. It enables the definition of cable elements and set its relative arrangements in a cross-section view. Post-processing features are also part of the program, enabling users to visualize the geometry, determining possible interferences only visible in a three-dimensional visualization module. Although a solver is also available to determine stress and displacements and, as a sub-product, the cable weight and equivalent stiffness, the CAD software can be easily integrated to other solvers, to provide pre and post processing resources. This paper gives a general description of the whole CAD system but focus on the three-dimensional module. Through the paper, an overview of the software is shown, pointing out the system requirements. Next, the user interface is described, showing its features and, to conclude, modeled cables geometries and some results are shown.

An interactive, visual approach to developing and applying parametric three-dimensional spatial grammars

2011 ◽  
Vol 25 (4) ◽  
pp. 333-356 ◽  
Author(s):  
Frank Hoisl ◽  
Kristina Shea
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Visual Development ◽  
General Level ◽  
Design Environment ◽  
Prototype Implementation ◽  
Left Hand ◽  
Spatial Grammar ◽  
The Creation ◽  
Definition Of

AbstractSpatial grammars are rule based, generative systems for the specification of formal languages. Set and shape grammar formulations of spatial grammars enable the definition of spatial design languages and the creation of alternative designs. Since the introduction of the underlying formalism, they have been successfully applied to different domains including visual arts, architecture, and engineering. Although many spatial grammars exist on paper, only a few, limited spatial grammar systems have been computationally implemented to date; this is especially true for three-dimensional (3-D) systems. Most spatial grammars are hard-coded, that is, once implemented, the vocabulary and rules cannot be changed without reprogramming. This article presents a new approach and prototype implementation for a 3-D spatial grammar interpreter that enables interactive, visual development and application of grammar rules. The method is based on a set grammar that uses a set of parameterized primitives and includes the definition of nonparametric and parametric rules, as well as their automatic application. A method for the automatic matching of the left hand side of a rule in a current working shape, including defining parametric relations, is outlined. A prototype implementation is presented and used to illustrate the approach through three examples: the “kindergarten grammar,” vehicle wheel rims, and cylinder cooling fins. This approach puts the creation and use of 3-D spatial grammars on a more general level and supports designers with facilitated definition and application of their own rules in a familiar computer-aided design environment without requiring programming.

Clearance Measurement of 3D Objects Using Accessibility Cone

2019 ◽  
Author(s):  
Masatomo Inui ◽  
Kouhei Nishimiya ◽  
Nobuyuki Umezu
Keyword(s):  
Graphics Processing Unit ◽  
Three Dimensional ◽  
Computation Time ◽  
Depth Information ◽  
Computation Method ◽  
Processing Unit ◽  
Three Dimensional Objects ◽  
Mechanical Products ◽  
Definition Of ◽  
Graphics Processing

Abstract Clearance is a basic parameter in the design of mechanical products, generally specified as the distance between two shape elements, for example, the width of a slot. This definition is unsuitable for evaluating the clearance during assembly or manufacturing tasks, where the depth information is also critical. In this paper, we propose a novel definition of clearance for the surface of three-dimensional objects. Unlike the typical methods used to define clearance, the proposed method can simultaneously handle the relationship between the width and depth in the clearance, and thus, obtain an intuitive understanding regarding the assembly and manufacturing capability of a product. Our definition is based on the accessibility cone of a point on the object’s surface; further, the peak angle of the accessibility cone corresponds to the clearance at this point. A computation method of the clearance is presented and the results of its application are demonstrated. Our method uses the rendering function of a graphics processing unit to compute the clearance. A large computation time necessary for the analysis is considered as a problem regarding the practical use of this clearance definition.

Application of the curvature scale space transform to the representation of three-dimensional models

2013 ◽  
Vol 18 (1) ◽  
pp. 23-29
Author(s):  
Dariusz Frejlichowski
Keyword(s):  
Computer Aided Design ◽  
Shape Representation ◽  
Three Dimensional ◽  
Shape Descriptor ◽  
3D Models ◽  
Scale Space ◽  
3D Shape ◽  
Three Dimensional Objects ◽  
Curvature Scale Space ◽  
Planar Shapes

Abstract In this paper an algorithm for the representation of 3D models is described and experimentally evaluated. Three-dimensional objects are becoming very popular recently and they are processed in various ways - analysed, retrieved, recognised, and so on. Moreover, they are employed in various aplications, such as virtual reality, entertainment, Internet, Computer Aided Design, or even in biometrics or medical imaging. That is why the development of appropriate algorithms for the representation of 3D objects is so important recently. These algorithms - so called 3D shape descriptors - are assumed to be invariant to particular transformations and deformations. One of the possible approaches is based on the projections of a 3D object into planar shapes and representation of them using a 2D shape descriptor. An algorithm realising this idea is described in this paper. Its first stage is based on the rendering of 20 2D projections, from various points of view. Later, the obtained projections are stored in a form of bitmaps and the Curvature Scale Space algorithm is applied for the description of the planar shapes extracted from them. The proposed approach is experimentally compared with several other 3D shape representation methods.

Mathematical Morphology in Multi-Dexel Representation

2009 ◽  
Author(s):  
Wei Zhao ◽  
Xiaoping Qian
Keyword(s):  
Mathematical Morphology ◽  
Three Dimensional ◽  
Spatial Relationship ◽  
Noise Removal ◽  
Theoretic Approach ◽  
Three Dimension ◽  
Three Dimensional Objects ◽  
Set Operations ◽  
Part Surface ◽  
Definition Of

Mathematical morphology provides a set-theoretic approach for spatial structure analysis and is particularly useful for describing the spatial relationship between a tool under motion and the part surface. However, its usage in three-dimension has so far been limited in part due to its computational complexity. This paper presents a multi-dexel based computer implementation of morphology operations. Three dimensional objects (tools and parts) are represented as collections of dexels (depth elements) in multiple directions. Morphology operations such as dilation and erosion are then converted to a series of 1D set operations in each direction. We show that our definition of multi-dexel is formal and our implementation is complete. We present our implementation results on three morphological applications: AFM image simulation, noise removal in 3D mesh, and NC path generation.

scholarly journals A PET palack és egyéb poliészter hulladékok újrafeldolgozása, újrahasznosítása

2021 ◽  
Vol 11 (22) ◽  
pp. 294-304
Author(s):  
Csaba Kutasi
Keyword(s):  
Raw Materials ◽  
Three Dimensional ◽  
Common Language ◽  
Moulding Process ◽  
Three Dimensional Objects ◽  
Pet Bottles ◽  
Injection Moulding Process ◽  
End Products ◽  
The Common ◽  
Definition Of

The scientific definition of polyethylene terephthalate (PET) changed for polyester in the common language. It was first manufactured in 1928 and the production of the fibre version started in 1941. Nowadays, 70% of artificial textile raw materials are polyester fibres and a significant amount of plastic waste is generated at the end of the life cycle of polyester clothing and other end products. The injection moulding process introduced in the 1970s made it possible to design and produce three-dimensional objects, and this resulted in the spreading of light, transparent, resistant and non-fragile PET bottles. Given that the degradation of PET is more than 450 years, the increase of recycling and reprocessing is an urgent pressure.

Computer-Aided Design of Curved Surfaces With Automatic Model Generation

1982 ◽  
Vol 104 (4) ◽  
pp. 817-824 ◽  
Author(s):  
S. M. Staley ◽  
R. B. Jerard ◽  
P. R. White
Keyword(s):  
Computer System ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Model Generation ◽  
Curved Surfaces ◽  
B Spline ◽  
Three Dimensional Objects ◽  
Computer Aided ◽  
Automatic Model Generation ◽  
Aided Design

The design and visualization of three-dimensional objects with curved surfaces have always been difficult. This paper describes a computer system that facilitates both the design and visualization of such surfaces. The system enhances the design of these surfaces by virtue of various interactive techniques coupled with the application of B-Spline theory. Visualization is facilitated by including a specially built model-making machine that produces three-dimensional foam models. Thus the system permits the designer to define an object and, with little additional effort, produce an inexpensive model of the object which is suitable for evaluation and presentation.

Dynamic Modelling of Blades Based on a Novel Curved Thin Walled Beam Theory

2018 ◽  
Author(s):  
Juan C. Jauregui ◽  
Diego Cardenas ◽  
Hugo Elizalde ◽  
Oliver Probst
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Dynamic Modelling ◽  
Beam Theory ◽  
General Description ◽  
B Splines ◽  
Out Of Plane ◽  
Thin Walled ◽  
Aided Design

There are several Thin-Walled Beam models for straight beams, but few TWB models consider beams with arbitrary curvatures. Although, a curved beam can be modelled using finite elements, the number of degrees of freedom is too large and a nonlinear dynamic solution is very cumbersome, if not impossible. In this work, a general description of arbitrary three-dimensional curves, based on the Frenet-Serret field frame, is applied to determine the dynamic stresses in wing turbines blades. The dynamic model is developed using the Isogeometric Analysis (IGA) and the in plane and out-of-plane curvature’s gradients are found in an Euler-type formulation, allowing the treatment of cases with highly-curved geometry. An Isogeometrical (IGA) formulation relies on a linear combination of Non-Uniform Rational B-Splines (NURBS) to represent not just the model’s geometry, a standard practice in most Computer-Aided Design (CAD) platforms, but also the unknown solution field of each sought variable. For the unified model hitherto described, these variables are represented by a NURBS curve.

Determination of Drying Times for Irregular Two and Three-Dimensional Objects

2003 ◽  
Vol 125 (6) ◽  
pp. 1190-1193 ◽  
Author(s):  
A. Z. Sahin and ◽  
I. Dincer
Keyword(s):  
Experimental Data ◽  
Analytical Model ◽  
Three Dimensional ◽  
Elliptic Cylinder ◽  
Drying Time ◽  
Shape Factors ◽  
High Agreement ◽  
Three Dimensional Objects ◽  
Infinite Slab

This paper deals with development of a new analytical model for determining the drying times of irregular-shaped multi-dimensional objects. Geometrically irregular two and three-dimensional products are approximated by elliptical cylinder and ellipsoidal shapes, respectively. Using experimental drying parameters that are available from the literature, drying times of irregular, multi-dimensional products are determined through the present models. Geometric shape factors for the elliptic cylinder and ellipsoid are employed and based on the reference drying time for an infinite slab. In addition, the present models are verified through comparison with experimental drying times of several food products. The accuracy of the predictions using the present models is then discussed, and a considerably high agreement is obtained between the predictions and experimental data.

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