METHDOS OF EFFECTIVE DESIGN FOR CREATING OF PARAMETRIC 3D-MODELS OF PRODUCTS USING THE INTERNAL CAPABILITIES OF CAD-PROGRAMS

2020 ◽  
Author(s):  
E. A. Petrakova
Keyword(s):  
Programming Languages ◽  
3D Model ◽  
Three Dimensional ◽  
3D Models ◽  
Parametric Modeling ◽  
Effective Control ◽  
Model Parameters ◽  
Internal Capabilities ◽  
Program Components ◽  
Effective Design

It is known that the development of a three-dimensional parametric model is a creative process, since the same 3D-model can be built in various ways. In the article the methods for effective design of parametric 3D-models with the help of internal capabilities of CAD-program without the use of programming languages (macros) is developed. Using the methods and recommendations discussed in the article on the example of Autodesk Inventor functionality will allow the engineer to design parametric three-dimensional products in CAD-programs in the most rational way, reducing the number of errors. Recommendations for effective control of 3D-model parameters during creating of Assembly parts and 2D-drawings are given. Using the functionality discussed in the article will be useful for engineers using parametric modeling methods to create typical products, optimization and analysis of structures, development of their own database of standard products that are not in the library of CAD-program components.

Effect of 3D Manipulatives on Students with Visual Impairments Who Are Learning Chemistry Constructs: A Pilot Study

2020 ◽  
Vol 114 (5) ◽  
pp. 370-381
Author(s):  
Derrick W. Smith ◽  
Sandra A. Lampley ◽  
Bob Dolan ◽  
Greg Williams ◽  
David Schleppenbach ◽  
...  
Keyword(s):  
Stem Education ◽  
3D Model ◽  
Atomic Orbital ◽  
Visual Impairments ◽  
Three Dimensional ◽  
3D Models ◽  
Specific Content ◽  
3D Printed ◽  
Printed Materials ◽  
Tactile Graphics

Introduction: The emerging technology of three-dimensional (3D) printing has the potential to provide unique 3D modeling to support specific content in science, technology, engineering, and mathematics (STEM) education, particularly chemistry. Method: Seventeen ( n = 17) students with visual impairments were provided direct instruction on chemistry atomic orbital content and allowed to use either print or tactile graphics or 3D models in rotating order. Participants were asked specific content questions based upon the atomic orbitals. Results: The students were asked two sets of comprehension questions: general and specific. Overall, students’ responses for general questions increased per iteration regardless of which manipulative was used. For specific questions, the students answered more questions correctly when using the 3D model regardless of order. When asked about their perceptions toward the manipulatives, the students preferred the 3D model over print or tactile graphics. Discussion: The findings show the potential for 3D printed materials in learning complex STEM content. Although the students preferred the 3D models, they all mentioned that a combination of manipulatives helped them better understand the material. Implications for practitioners: Practitioners should consider the use of manipulatives that include 3D printed materials to support STEM education.

Models partition for 3D printing objects using skeleton

2017 ◽  
Vol 23 (1) ◽  
pp. 54-64 ◽  
Author(s):  
Xiaotong Jiang ◽  
Xiaosheng Cheng ◽  
Qingjin Peng ◽  
Luming Liang ◽  
Ning Dai ◽  
...  
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Principal Component ◽  
3D Models ◽  
Sweep Method ◽  
Final Model ◽  
Content Type ◽  
Working Volume ◽  
Minima Rule ◽  
The Greedy Algorithm

Purpose It is a challenge to print a model with the size that is larger than the working volume of a three-dimensional (3D) printer. The purpose of this paper is to present a feasible approach to divide a large model into small printing parts to fit the volume of a printer and then assemble these parts into the final model. Design/methodology/approach The proposed approach is based on the skeletonization and the minima rule. The skeleton of a printing model is first extracted using the mesh contraction and the principal component analysis. The 3D model is then partitioned preliminarily into many smaller parts using the space sweep method and the minima rule. The preliminary partition is finally optimized using the greedy algorithm. Findings The skeleton of a 3D model can effectively represent a simplified version of the geometry of the 3D model. Using a model’s skeleton to partition the model is an efficient way. As it is generally desirable to have segmentations at concave creases and seams, the cutting position should be located in the concave region. The proposed approach can partition large models effectively to well retain the integrity of meaningful parts. Originality/value The proposed approach is new in the rapid prototyping field using the model skeletonization and the minima rule. Based on the authors’ knowledge, there is no method that concerns the integrity of meaningful parts for partitioning. The proposed method can achieve satisfactory results by the integrity of meaningful parts and assemblability for most 3D models.

scholarly journals Influence of Geometric Features Associativity of CAD Class Models on the Process of Their Updating – Comparative Analysis

2021 ◽  
Author(s):  
Grzegorz Świaczny
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Optimal Solution ◽  
3D Models ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Initial Design ◽  
The Individual ◽  
Class Models ◽  
Positive Effect

This article deals with the topic of one of the most important features of modern CAx class systems – associativity. The term refers to the ability to form relations (links) between two or more objects (in terms of their selected features), and with the consequence creating an associative (linked) three-dimensional model. The author pays special attention to the very process of creating relations between objects, as it has a key impact on the structural stability of CAD class models, and thus on their susceptibility to possible modifications. To show that not all associativity brings a positive effect, the author presents two examples of its implementation. In order to emphasize the influence of the method of linking individual elements, both examples are based on the same 3D model – a thin-walled part with a positioning pin. That means the geometric form of the default part is the same, whereas only relations of the individual objects of the 3D model change. In the first scenario, correctly defined relations between objects make that the positioning pin offset does not affect the initial design conditions. The second scenario shows an incorrect implementation of associativity, as a result of which the same operation of positioning pin offset gives non-compliance with the initial design conditions and with the consequence an undesirable change in its geometry. The article is an attempt to draw attention to the fact that the associative structure of 3D models is not always equal to the optimal solution. Only the well-thought-out nature of associativity allows to use all its advantages.

scholarly journals METHODS FOR MODELS PARAMETERS ESTIMATE TO SOLVE PROBLEMS ON 3D RECONSTRUCTION OF REAL OBJECTS COMPLEX MODELS

2016 ◽  
Vol 2016 (3) ◽  
pp. 233-242 ◽  
Author(s):  
Владислав Колякин ◽  
Vladislav Kolyakin ◽  
Владимир Аверченков ◽  
Vladimir Averchenkov ◽  
Максим Терехов ◽  
...  
Keyword(s):  
Computer Games ◽  
Three Dimensional ◽  
3D Models ◽  
Model Parameters ◽  
Complex Objects ◽  
Image Brightness ◽  
Real Objects ◽  
Complex Models ◽  
Three Dimensional Models ◽  
Definition Of

Virtual threedimensional (3 D) models of complex objects are used in many fields of science and engineering, such as architecture, industry, medicine, robotics. Besides, 3D models are used in geoinformation systems, computer games, virtual and supplemented reality and so on. Three dimensional models can be formed in dif-ferent ways, one of which consists in 3 D reconstruc-tion. One of the stages of the 3 D reconstruction of complex models of real objects is a definition of the mathematical models of geometric primitives emphasized on the image. One of the ways for the estimate of model parameters is a method of Hough vote and its modifications – Hough probabilistic transformation, Hough random transformation, Hough hierarchical transformation, phase space blurriness, use of a gra-dient of image brightness and so on. As an alternative way for models selection is a choice of suitable points from a set of data.

Design Modification of Additive Manufacturing Parts Using Texture Information of 3D Model

2019 ◽  
Vol 825 ◽  
pp. 19-30
Author(s):  
Tsung Chien Wu ◽  
Jiing Yih Lai ◽  
Yu Wen Tseng ◽  
Chao Yaug Liao ◽  
Ju Yi Lee
Keyword(s):  
Additive Manufacturing ◽  
3D Model ◽  
Three Dimensional ◽  
Texture Mapping ◽  
3D Models ◽  
Surface Shape ◽  
Design Features ◽  
Design Modification ◽  
Texture Information ◽  
Triangular Model

Additive manufacturing (AM) has been commonly used for the prototyping of three-dimensional (3D) models. The input model of the AM technology is a triangular model representing the surface shape of an object. The design features on a triangular model are generally not clear as the vertices are irregularly distributed. If design modification is necessary, it is difficult to segment and extract the meshes from the model. The objective of this study is to propose a method for extracting the design features on an object model by using the texture information. A 3D color model including a triangular model representing the object shape and a texture map describing the object texture is employed. The 3D model is generated by using a set of object images captured from different views surrounding the object. A texture mapping algorithm is then employed to generate the texture map corresponding to the 3D model. With both meshes and texture displayed in a texture mode, a region extraction technique is employed to extract the design features. All parts separated can then be fabricated with an AM machine, and assembled for checking the feasibility of design modification. Several products are employed to demonstrate the feasibility of the proposed technique.

scholarly journals Problems of Creation and Usage of 3D Model of Structures and Theirs Possible Solution

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 181 ◽  
Author(s):  
Dalibor Bartonek ◽  
Michal Buday
Keyword(s):  
Computer Aided Design ◽  
3D Model ◽  
Three Dimensional ◽  
3D Models ◽  
Cad System ◽  
Building Models ◽  
Special Cad ◽  
Aided Design ◽  
The Church

This article describes problems that occur when creating three-dimensional (3D) building models. The first problem is geometric accuracy; the next is the quality of visualization of the resulting model. The main cause of this situation is that current Computer-Aided Design (CAD) software does not have sufficient means to precision mapping the measured data of a given object in field. Therefore the process of 3D model creation is mainly a relatively high proportion of manual work when connecting individual points, approximating curves and surfaces, or laying textures on surfaces. In some cases, it is necessary to generalize the model in the CAD system, which degrades the accuracy and quality of field data. The article analyzes these problems and then recommends several variants for their solution. There are described two basic methods: using topological codes in the list of coordinates points and creating new special CAD features while using Python scripts. These problems are demonstrated on examples of 3D models in practice. These are mainly historical buildings in different locations and different designs (brick or wooden structures). These are four sacral buildings in the Czech Republic (CR): the church of saints Johns of Brno-Bystrc, the Church of St. Paraskiva in Blansko, further the Strejc’s Church in Židlochovice, and Church of St. Peter in Alcantara in Karviná city. All of the buildings were geodetically surveyed by terrestrial method while using total station. The 3D model was created in both cases in the program AUTOCAD v. 18 and MicroStation.

Three-Dimensional Kernel Development With Parasolid for Integral Sheet Metal Design With Higher Order Bifurcations

2009 ◽  
Author(s):  
Thomas Rollmann ◽  
Anselm Schu¨le ◽  
Reiner Anderl ◽  
Youssef Chahadi
Keyword(s):  
Product Design ◽  
Programming Languages ◽  
Sheet Metal ◽  
Three Dimensional ◽  
3D Models ◽  
Higher Order ◽  
Boundary Representation ◽  
Generation Process ◽  
3D Cad ◽  
Metal Design

The technology of linear flow splitting to produce bifurcated sheet metal structures is researched by the collaborative research center 666 since 2005. So far the product design process is supported by 3D-CAD models on the basis of User-Defined-Features in standard 3D-CAD systems. This paper now presents a new approach for generating 3D-models of integral sheet metal design products with higher order bifurcations based on a low-level 3D-kernel. The emphasis is placed on two aspects, namely the processing of the model’s topology and geometry as well as the software implementation. First, a methodology for the generation and manipulation of the geometry and topology of the Boundary Representation (B-Rep) structure is proposed. This methodology is integrated into an algorithm-based product design approach, which enables engineers to plan and design their complete draft for bifurcated sheet metal parts in an automated, computer aided way. Further functionalities to support the subsequent manufacturing process are developed and integrated. The idea is then implemented by developing a 3D-CAD application using the B-Rep CAD-kernel Parasolid. The programming framework. NET has been chosen for the development of the software on a Windows NT platform using the object-oriented C++ and C# programming languages. The work presented here has significant implications on the quality, accurateness and efficiency of the product generation process of sheet metal products with higher order bifurcations.

Fabrication of 3D Models for Microtia Reconstruction Using Smartphone-Based Technology

2021 ◽  
pp. 000348942110240
Author(s):  
Peng You ◽  
Yi-Chun Carol Liu ◽  
Rodrigo C. Silva
Keyword(s):  
3D Model ◽  
Low Cost ◽  
Tertiary Care ◽  
Three Dimensional ◽  
Basic Research ◽  
3D Models ◽  
University Hospital ◽  
Patient Specific ◽  
Surface Scanning ◽  
Barrier To Entry

Objective: Microtia reconstruction is technically challenging due to the intricate contours of the ear. It is common practice to use a two-dimensional tracing of the patient’s normal ear as a template for the reconstruction of the affected side. Recent advances in three-dimensional (3D) surface scanning and printing have expanded the ability to create surgical models preoperatively. This study aims to describe a simple and affordable process to fabricate patient-specific 3D ear models for use in the operating room. Study design: Applied basic research on a novel 3D optical scanning and fabrication pathway for microtia reconstruction. Setting: Tertiary care university hospital. Methods: Optical surface scanning of the patient’s normal ear was completed using a smartphone with facial recognition capability. The Heges application used the phone’s camera to capture the 3D image. The 3D model was digitally isolated and mirrored using the Meshmixer software and printed with a 3D printer (MonopriceTM Select Mini V2) using polylactic acid filaments. Results: The 3D model of the ear served as a helpful intraoperative reference and an adjunct to the traditional 2D template. Collectively, time for imaging acquisition, editing, and fabrication was approximately 3.5 hours. The upfront cost was around $210, and the recurring cost was approximately $0.35 per ear model. Conclusion: A novel, low-cost approach to fabricate customized 3D models of the ear is introduced. It is feasible to create individualized 3D models using currently available consumer technology. The low barrier to entry raises the possibility for clinicians to incorporate 3D printing into various clinical applications.

scholarly journals Cortical Depth-Dependent Modeling of Visual Hemodynamic Responses

2020 ◽  
Author(s):  
T.C. Lacy ◽  
P.A. Robinson ◽  
K.M. Aquino ◽  
J.C. Pang
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Blood Oxygen Level Dependent ◽  
Flow Dynamics ◽  
Model Parameters ◽  
Blood Oxygen ◽  
Blood Oxygen Level ◽  
Bold Responses ◽  
Hemodynamic Model ◽  
Blood Flow Dynamics

AbstractA physiologically based three-dimensional (3D) hemodynamic model is used to predict the experimentally observed blood oxygen level dependent (BOLD) responses versus the cortical depth induced by visual stimuli. Prior 2D approximations are relaxed in order to analyze 3D blood flow dynamics as a function of cortical depth. Comparison of the predictions with experimental data for typical stimuli demonstrates that the full 3D model matches at least as well as previous approaches while requiring significantly fewer assumptions and model parameters.

scholarly journals On the fully 3D simulations of thermoelastic models defined in plate and shell geometries

2012 ◽  
Author(s):  
Brice Bognet ◽  
Adrien Leygue ◽  
Francisco Chinesta
Keyword(s):  
Computational Complexity ◽  
Dimensionality Reduction ◽  
3D Model ◽  
Three Dimensional ◽  
3D Models ◽  
Polymer Processing ◽  
Two Dimensional ◽  
Composites Manufacturing ◽  
Plate And Shell ◽  
Separated Representation

Many models in polymer processing and composites manufacturing are defined in degenerated three-dimensional domains (3D), involving plate or shell geometries. The reduction of models from 3D to two-dimensional (2D) is not obvious when complex physics or particular geometries are involved. The hypotheses to be introduced for reaching this dimensionality reduction are unclear, and most of the possible proposals will have a narrow interval of validity. The only gateway is to explore new discretisation strategies able to circumvent or at least alleviate the drawbacks related to mesh-based discretisations of fully 3D models defined in plate or shell domains. Appropriate separated representation of the involved fields within the context of the proper generalised decomposition allows solving the fully 3D model by keeping a 2D characteristic computational complexity.

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