scholarly journals Comparison of Computer Extended Descriptive Geometry (CeDG) with CAD in the Modeling of Sheet Metal Patterns

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 685
Author(s):  
Manuel Prado-Velasco ◽  
Rafael Ortiz-Marín

The emergence of computer-aided design (CAD) has propelled the evolution of the sheet metal engineering field. Sheet metal design software tools include parameters associated to the part’s forming process during the pattern drawing calculation. Current methods avoid the calculation of a first pattern drawing of the flattened part’s neutral surface, independent of the forming process, leading to several methodological limitations. The study evaluates the reliability of the Computer Extended Descriptive Geometry (CeDG) approach to surpass those limitations. Three study cases that cover a significative range of sheet metal systems are defined and the associated solid models and patterns’ drawings are computed through Geogebra-based CeDG and two selected CAD tools (Solid Edge 2020, LogiTRACE v14), with the aim of comparing their reliability and accuracy. Our results pointed to several methodological lacks in LogiTRACE and Solid Edge that prevented to solve properly several study cases. In opposition, the novel CeDG approach for the computer parametric modeling of 3D geometric systems overcame those limitations so that all models could be built and flattened with accuracy and without methodological limitations. As additional conclusion, the success of CeDG suggests the necessity to recover the relevance of descriptive geometry as a key core in graphic engineering.

Author(s):  
Felicitas Pielsticker ◽  
Ingo Witzke ◽  
Amelie Vogler

AbstractDigital media have become increasingly important in recent years and can offer new possibilities for mathematics education in elementary schools. From our point of view, geometry and geometric objects seem to be suitable for the use of computer-aided design software in mathematics classes. Based on the example of Tinkercad, the use of CAD software — a new and challenging context in elementary schools — is discussed within the approach of domains of subjective experience and the Toulmin model. An empirical study examined the influence of Tinkercad on fourth-graders’ development of a model of a geometric solid and related reasoning processes in mathematics classes.


Author(s):  
John G. Cherng

Abstract This paper presents the innovative approaches that can be implemented in teaching descriptive geometry by using a Computer-Aided-Design-Drafting (CADD) software. Examples of line relations, line/surface relations, and plane/cylindrical solid intersections are given in the paper. The paper first discusses the principles of descriptive geometry, and then focuses on how these principles can be applied in a CADD environment. In addition, new methods that take advantage of CADD are also provided. The paper emphasizes creativity while solving descriptive problems by using a CADD software. Although all examples illustrated in CADKEY, the concepts revealed in this paper can be applied to other 3-D CADD software, such as AutoCAD 10 and will significantly improve the engineering student’s CADD skills.


2009 ◽  
Vol 626-627 ◽  
pp. 273-278 ◽  
Author(s):  
X.J. Li ◽  
Ming Zhe Li ◽  
C.G. Liu ◽  
Zhong Yr Cai

Based on Multi-Point (MP) forming technology and Single-Point Incremental (SPI) forming technology, MP-SPI combined forming method for sheet metal is proposed, the principle and two different forming techniques are illustrated firstly. Then the paper is focused on numerical analysis for the novel forming technique with explicit Finite Element (FE) algorithm. During simulation of spherical work-piece, dimpling occurs as a main forming defect in MP-SPI combined forming process. Simulation results show that the dimpling defect can be suppressed effectively by using elastic cushion. An appropriate thickness of elastic cushion is necessary to prevent dimpling. And also the deformation of the work-piece is sensitive to the shape of elastic cushion. The combined forming test shows that the numerical simulation result is closed to the experimental result.


2016 ◽  
Vol 823 ◽  
pp. 396-401
Author(s):  
Adrian Cuzmoş ◽  
Dorian Nedelcu ◽  
Constantin Viorel Câmpian ◽  
Cristian Fănică ◽  
Ana Maria Budai

The paper presents a method developed and used by the CCHAPT researchers for the graphic plotting of the index tests results for hydraulic turbines, the comparison of the efficiency curves resulted from testing to those obtained by the model transposition [1] i.e. the determination and comparison of the existing combinatory cam with that obtained from tests.The method presented in the paper was born from the need for processing and presenting the results of index tests within the shortest delay and eliminating the errors that might occur in the results plotting.


2020 ◽  
Vol 10 (24) ◽  
pp. 9029
Author(s):  
Bokyeong Lee ◽  
Hyeonggil Choi ◽  
Byongwang Min ◽  
Dong-Eun Lee

In this study, by applying the developed formwork automation design software to three target structures, we reviewed the applicability of the formwork automation design software for the aluminum formwork. To apply the formwork automation design software, we built an aluminum formwork library based on the conversion of two-dimensional (2D) computer-aided design (CAD) data to three-dimensional building information modeling data for all the components of the aluminum formwork. The results of the automated formwork layout on the target structures using the formwork automation design software confirmed that the wall and deck members were laid out by the set algorithm according to the formwork size and direction. However, because of the limited functionality of the software, the level of completion of the formwork layout was found to be lower than that of the manual formwork layout based on 2D CAD data. The currently developed software is based on a simple algorithm, but has a drawback in that the automated layout is limited to only some of its members. Therefore, additional research should be conducted on the development of advanced software through the diversification of the algorithm, automation of preprocessing of the mesh, and analysis of the relationships of all the members comprising the formwork.


PLoS ONE ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. e0226322
Author(s):  
Nelson Massanobu Sakaguti ◽  
Mário Marques Fernandes ◽  
Luiz Eugênio Nigro Mazzilli ◽  
Juan Antonio Cobo Plana ◽  
Fernanda Capurucho Horta Bouchardet ◽  
...  

2005 ◽  
Vol 127 (12) ◽  
pp. 32-34
Author(s):  
Jean Thilmany

This article discusses that how mechanical engineers will pair their already-familiar computer-aided design software with not-so-familiar three-dimensional (3D) displays for true 3D design. This is in accordance to a number of vendors' intent on supplying the newfangled computer monitors, within the next two decades. Although some of the devices are already on the market, affordable 3D monitors and displays seem to be more than a decade away, according to one university professor at work on such a project. Widespread adoption is still hindered by factors such as cost, software availability, and lack of a mouse-like device needed to interact with what’s on screen. Over the past 25 years, mechanical engineers have witnessed evolutionary change in design methods-from pen and paper to two-dimensional software and now to 3-D computer-aided design. While software makers have stepped up with sleeker and faster modeling capabilities, visualization lags. Computer users two decades out will carry out all business, web surfing, and gaming on 3-D displays. That next generation may well find the very idea of 2-D monitors to be as dated as record albums seem to teenagers today.


Author(s):  
Jack Chang ◽  
Mark Ganter ◽  
Duane Storti

Abstract Computer-aided design/manufacturing (CAD/CAM) systems intended to support automated design and manufacturing applications such as shape generation and solid free-form fabrication (SFF) must provide not only methods for creating and editing models of objects to be manufactured, but also methods for interrogating the models. Interrogation refers to any process that derives information from the model. Typical interrogation tasks include determine surface area, volume or inertial properties, computing surface points and normals for rendering, and computing slice descriptions for SFF. While currently available commercial modeling systems generally employ a boundary representation (B-rep) implementation of solid modeling, research efforts have considered implicit modeling schemes as a potential source of improved robustness. Implicit implementations are available for a broad range of modeling operations, but interrogation operations have been widely considered too costly for many applications. This paper describes a method based on interval analysis for interrogating implicit solid models that aims at achieving both robustness and efficiency.


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