Triangular Mesh and Boundary Representation Combined Approach for 3D CAD Lightweight Representation for Collaborative Product Development

2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Cong Hong Phong Nguyen ◽  
Young Choi
Keyword(s):  
Product Development ◽  
Computer Aided Design ◽  
Large Scale ◽  
Three Dimensional ◽  
Original Data ◽  
Triangular Mesh ◽  
Boundary Representation ◽  
Collaborative Product Development ◽  
3D Cad ◽  
Cad Models

The lightweight representation of three-dimensional computer-aided design (3D CAD) models has drawn much attention from researchers as its usefulness in collaborative product development is vast. Existing approaches are mostly based on feature depression or mesh-based simplification. In this article, a new approach for 3D CAD lightweight representation based on combining triangular mesh representation and boundary representation (B-rep) is proposed. The corresponding data structure as well as the conversion method from original data given in B-rep was developed. Considered as an essential application in collaborative product development, a case study on the visualization process of large-scale assembly models represented in the proposed lightweight representation was also conducted. The validation of the approach was performed via experiments with 3D CAD models in SAT format and by benchmarking with the conventional all-faceted approach with the same level of mesh resolution.

scholarly journals Automatized Evaluation of Students’ CAD Models

2021 ◽  
Vol 11 (4) ◽  
pp. 145
Author(s):  
Nenad Bojcetic ◽  
Filip Valjak ◽  
Dragan Zezelj ◽  
Tomislav Martinec
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Computer Application ◽  
Test Cases ◽  
Cad Model ◽  
Computer Solution ◽  
3D Cad ◽  
Computer Aided ◽  
Cad Models ◽  
Aided Design

The article describes an attempt to address the automatized evaluation of student three-dimensional (3D) computer-aided design (CAD) models. The driving idea was conceptualized under the restraints of the COVID pandemic, driven by the problem of evaluating a large number of student 3D CAD models. The described computer solution can be implemented using any CAD computer application that supports customization. Test cases showed that the proposed solution was valid and could be used to evaluate many students’ 3D CAD models. The computer solution can also be used to help students to better understand how to create a 3D CAD model, thereby complying with the requirements of particular teachers.

Measured Data Alignments for Monitoring Metal Additive Manufacturing Processes Using Laser Powder Bed Fusion Methods

2020 ◽  
Author(s):  
Shaw C. Feng ◽  
Yan Lu ◽  
Albert T. Jones
Keyword(s):  
Coordinate System ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Ex Situ ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Alignment Procedure ◽  
3D Cad ◽  
Data Alignment ◽  
Cad Models

Abstract The number and types of measurement devices used for monitoring and controlling Laser-Based Powder Bed Fusion of Metals (PBF-LB/M) processes and inspecting the resulting AM metal parts have increased rapidly in recent years. The variety of the data collected by such devices has increased, and the veracity of the data has decreased simultaneously. Each measurement device generates data in a unique coordinate system and in a unique data type. Data alignment, however, is required before 1) monitoring and controlling PBF-LB/M processes, 2) predicting the material properties of the final part, and 3) qualifying the resulting AM parts can be done. Aligned means all data must be transformed into a single coordinate system. In this paper, we describe a new, general data-alignment procedure and an example based on PBF-LB/M processes. The specific data objects used in this example include in-situ photogrammetry, thermography, ex-situ X-ray computed tomography (XCT), coordinate metrology, and computer-aided design (CAD) models. We propose a data-alignment procedure to align the data from melt pool images, scan paths, layer images, XCT three-dimensional (3D) model, coordinate measurements, and the 3D CAD model.

Profiling the Desirable CAD Trainee: Technical Background, Personality Attributes, and Learning Preferences

2009 ◽  
Vol 131 (12) ◽  
Author(s):  
Ramsey F. Hamade
Keyword(s):  
Learning Styles ◽  
Learning Style ◽  
Computer Aided Design ◽  
Mechanical Design ◽  
Three Dimensional ◽  
Learning Preferences ◽  
Actual Behavior ◽  
3D Cad ◽  
Active Sensor ◽  
Cad Models

This research aims to explore some of the underlying reasoning for why some individuals acquire mechanical computer-aided design (CAD) skills with relative ease while some others seem to falter. A methodical study was performed by monitoring 74 mechanical engineering seniors (over a 3 year period) in a semester-long formal training on a commercial three-dimensional (3D) CAD package (PRO/ENGINEER, version WILDFIRE). The study methodically explored the trainees’ (1) technical background, (2) personality attributes, and (3) learning preferences. Investigating the technical background included quantifying the trainees’ following technical foundations: basic math, advanced math, CAD-related math, computer science and engineering, methodologies related to CAD, graphics, and mechanical design. Determining the trainees’ personality attributes included exploring their willingness-to-learn CAD, perception, gauging their actual behavior (practice), and CAD syntax learned throughout the training. Trainees’ learning preferences were determined according to the index of learning styles (ILS). Furthermore, and in order to assess the trainees’ progress in CAD knowledge acquisition, competency tests were conducted at four intervals throughout the semester-long study. The assessment involved hands-on modeling of CAD test parts of comparable complexity. At the conclusion of the study, statistical methods were used to correlate the trainees’ attributes with their monitored performance. Only a fraction (17 out of a class of 74 trainees or 1 in 4) of the trainees were found to fit the “star CAD trainee” mold, which is defined here as someone who is fast on the tube and perceptive enough to see through the procedure of building progressively more sophisticated CAD models. A profile of the star CAD trainee character emerges as an individual who is technically competent, perceptive, and motivated. The study also reveals these most desirable trainees to possess an active, sensor, visual, and sequential learning style.

Virtual concurrent product development of plastic injection moulds

2000 ◽  
Vol 214 (2) ◽  
pp. 165-168 ◽  
Author(s):  
G Britton ◽  
T S Beng ◽  
Y Wang
Keyword(s):  
Product Development ◽  
Collaborative Design ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Prototype System ◽  
Computer Aided ◽  
Cad Cam ◽  
Cad Models ◽  
Aided Design ◽  
Plastic Injection

This paper describes three approaches for virtual product development of plastic injection moulds. The first is characterized by the use of three-dimensional computer aided design (CAD) for product design, two-dimensional drafting for mould design and three-dimensional computer aided design/manufacture (CAD/CAM) for mould manufacture. The second is characterized by the use of three-dimensional CAD models by all three participants, but between any two participants some form of file conversion is normally required because different CAD systems are used. The first two approaches share one common feature: the models are passed serially from the product designer to the mould designer and on to the toolmaker. They represent current practice in industry. The third approach is a proposed collaborative design process. Participants can work concurrently on the same model, sharing their knowledge and experience. The process is currently being refined and will be validated later this year with a prototype system based on Unigraphics iMAN software.

Graph-Based Simplification of Feature-Based Three-Dimensional Computer-Aided Design Models for Preserving Connectivity

2015 ◽  
Vol 15 (3) ◽  
Author(s):  
Soonjo Kwon ◽  
Byung Chul Kim ◽  
Duhwan Mun ◽  
Soonhung Han
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Evaluation Metrics ◽  
Prototype System ◽  
Cad Model ◽  
3D Cad ◽  
Computer Aided ◽  
Cad Models ◽  
Feature Based ◽  
Aided Design

The required level of detail (LOD) of a three-dimensional computer-aided design (3D CAD) model differs according to its purpose. It is therefore important that users are able to simplify a highly complex 3D CAD model and create a low-complexity one. The simplification of a 3D CAD model requires the application of a simplification operation and evaluation metrics for the geometric elements of the 3D CAD model. The evaluation metrics are used to select those elements that should be removed. The simplification operation removes selected elements in order to simplify the 3D CAD model. In this paper, we propose the graph-based simplification of feature-based 3D CAD models using a method that preserves connectivity. First, new evaluation metrics that consider the discrimination priority among several simplification criteria are proposed. Second, a graph-based refined simplification operation that prevents the separation of a feature-based 3D CAD model into multiple volumes is proposed. Finally, we verify the proposed method by implementing a prototype system and performing simplification experiments using feature-based 3D CAD models.

scholarly journals A New Car Concept Developed with Stylistic Design Engineering (SDE)

Inventions ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 30
Author(s):  
Giampiero Donnici ◽  
Leonardo Frizziero ◽  
Alfredo Liverani ◽  
Giulio Buscaroli ◽  
Luna Raimondo ◽  
...  
Keyword(s):  
Design Process ◽  
Computer Aided Design ◽  
Quality Function Deployment ◽  
Design Research ◽  
Design Method ◽  
Three Dimensional ◽  
Design Engineering ◽  
3D Cad ◽  
Cad Models ◽  
New City

In this work, a structured design method, the Stylistic Design Engineering (SDE), is applied for the construction of a new minivan car, in particular a new city car, which we will call FIAT 600 Omega. The SDE, or Stylistic Design Engineering, is a structured engineering method for carrying out automotive design projects. The SDE method consists of six different phases: (1) Analysis of stylistic trends; (2) Sketches; (3) 2D Computer Aided Design (CAD) drawings; (4) 3D CAD models; (5) Rendering; (6) Solid stylistic model (also called style maquette). This project deals with the external redesign of the Fiat 600 multiple, a small minivan which was very successful in the 1950s and 1960s. SDE is a methodology consisting of various technologies and design methodologies that will be further explained in detail, such as the Pininfarina method, the Quality Function Deployment (QFD) method, Benchmarking (BM), and Top Flop Analysis (TPA). The work was organized according to the different phases. Initially, the Fiat style was studied, in particular the style of the FIAT 600 MULTI PURPOUSE VEHICLE (MPV). This step is essential to better understand the characteristics of the brand and also the main characteristics carried out over the decades. Then we moved on to the freehand sketching phase, based on what we learned in the previous phase of the study. When a satisfactory shape was found for the new car, by analyzing and discarding the different proposals of the various types of style, we proceeded to the evaluation of the proportions and dimensions through two-dimensional drawings and finally we obtained the three-dimensional shape of the new car thanks to 3D CAD software and rendering software. Many advantages in the industrial world SDE takes together with its development. In fact, until the early 2000s, car design and styling was considered quite a craft activity, not a technical or scientific one, mostly based on the great capability of famous car designers and masters, just like Giugiaro, Zagato, Bertone, Pininfarina, Stephenson, Bangle, etc. Then, thanks to the industrial activity of Eng. Lorenzo Ramacciotti, former CEO of Pininfarina Spa and Mechanical Engineer, and also thanks to the academic studies developed at ALMA MATER STUDIORUM University of Bologna, SDE became the object of attention, because it is able to systematize the car design process and reduce costs. With SDE, a good design research or an industrial product development team can complete a car design project, also without the presence of a mentor. Car Design Process finally becomes with SDE a scientific method; Car Design becomes with SDE an industrial method. Industrial needs are nice products made in a short time; SDE is structured to attend these issues. Industrial challenges follow innovation, in shape and functionality; SDE is able to recognize innovation. Industrial benefits can be reached with SDE, ensuring beautiful aesthetic projects are realized systematically and with low costs.

scholarly journals An isogeometric b-rep mortar-based mapping method for non-matching grids in fluid-structure interaction

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Andreas Apostolatos ◽  
Altuğ Emiroğlu ◽  
Shahrokh Shayegan ◽  
Fabien Péan ◽  
Kai-Uwe Bletzinger ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Fluid Structure Interaction ◽  
Mapping Method ◽  
Boundary Representation ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Discrete Surface ◽  
Cad Models ◽  
Volume Method ◽  
Aided Design

AbstractIn this study the isogeometric B-Rep mortar-based mapping method for geometry models stemming directly from Computer-Aided Design (CAD) is systematically augmented and applied to partitioned Fluid-Structure Interaction (FSI) simulations. Thus, the newly proposed methodology is applied to geometries described by their Boundary Representation (B-Rep) in terms of trimmed multipatch Non-Uniform Rational B-Spline (NURBS) discretizations as standard in modern CAD. The proposed isogeometric B-Rep mortar-based mapping method is herein extended for the transformation of fields between a B-Rep model and a low order discrete surface representation of the geometry which typically results when the Finite Volume Method (FVM) or the Finite Element Method (FEM) are employed. This enables the transformation of such fields as tractions and displacements along the FSI interface when Isogeometric B-Rep Analysis (IBRA) is used for the structural discretization and the FVM is used for the fluid discretization. The latter allows for diverse discretization schemes between the structural and the fluid Boundary Value Problem (BVP), taking into consideration the special properties of each BVP separately while the constraints along the FSI interface are satisfied in an iterative manner within partitioned FSI. The proposed methodology can be exploited in FSI problems with an IBRA structural discretization or to FSI problems with a standard FEM structural discretization in the frame of the Exact Coupling Layer (ECL) where the interface fields are smoothed using the underlying B-Rep parametrization, thus taking advantage of the smoothness that the NURBS basis functions offer. All new developments are systematically investigated and demonstrated by FSI problems with lightweight structures whereby the underlying geometric parametrizations are directly taken from real-world CAD models, thus extending IBRA into coupled problems of the FSI type.

Investigating the Use of Large-Scale Immersive Computing Environments in Collaborative Design

2014 ◽  
Author(s):  
Meisha Rosenberg ◽  
Judy M. Vance
Keyword(s):  
Design Process ◽  
Collaborative Design ◽  
Large Scale ◽  
Design Teams ◽  
Team Members ◽  
3D Cad ◽  
Cad Models ◽  
Computing Environments ◽  
Design Ideas ◽  
Human Motions

Successful collaborative design requires in-depth communication between experts from different disciplines. Many design decisions are made based on a shared mental model and understanding of key features and functions before the first prototype is built. Large-Scale Immersive Computing Environments (LSICEs) provide the opportunity for teams of experts to view and interact with 3D CAD models using natural human motions to explore potential design configurations. This paper presents the results of a class exercise where student design teams used an LSICE to examine their design ideas and make decisions during the design process. The goal of this research is to gain an understanding of (1) whether the decisions made by the students are improved by full-scale visualizations of their designs in LSICEs, (2) how the use of LSICEs affect the communication of students with collaborators and clients, and (3) how the interaction methods provided in LSICEs affect the design process. The results of this research indicate that the use of LSICEs improves communication among design team members.

scholarly journals PARAMETRIC DESIGN OF DELTA ROBOT

2016 ◽  
Vol 4 ◽  
pp. 803-806 ◽  
Author(s):  
Mert Gürgen ◽  
Cenk Eryılmaz ◽  
Vasfi Emre Ömürlü
Keyword(s):  
Computer Aided Design ◽  
Parametric Design ◽  
Three Dimensional ◽  
Theoretical Data ◽  
Technical Solution ◽  
3D Cad ◽  
3D Data ◽  
Kinematic Behavior ◽  
Delta Robot ◽  
Aided Design

This article describes a sophisticated determination and presentation of a workspace volume for a delta robot, with consideration of its kinematic behavior. With the help of theoretical equations, optimization is performed with the aid of the stiffness and dexterity analysis. Theoretical substructure is coded in Matlab and three-dimensional (3D) data for delta robot are developed in computer-aided design (CAD) environment. In later stages of the project, both 3D and theoretical data are linked together and thus, with the changing design parameter of the robot itself, the Solidworks CAD output adapts and regenerates output with a new set of parameters. To achieve an optimum workspace volume with predefined parameters, a different set of robot parameters are iterated through design optimization in Matlab, and the delta robot design is finalized and illustrated in the 3D CAD environment, Solidworks. This study provides a technical solution to accomplish a generic delta robot with optimized workspace volume.

Geometric Reasoning for the Coding of CAD Models

1995 ◽  
Author(s):  
A. Z. Qamhiyah ◽  
B. Benhabib ◽  
R. D. Venter
Keyword(s):  
Computer Aided Design ◽  
Feature Recognition ◽  
Effective Means ◽  
Boundary Representation ◽  
Cad Model ◽  
Cad System ◽  
Cad Models ◽  
Form Features ◽  
Feature Based Design ◽  
Design Retrieval

Abstract Many of today’s concurrent product-development cycles depend on the utilization of intelligent Computer-Aided Design (CAD) systems. Thus, it would be essential to provide CAD users with effective means for interacting with the CAD system and its database. This paper addresses the development of a boundary-based coding procedure for CAD models. Coding the geometric and processing characteristics of objects, based on their CAD model representation, has been long recognized as an effective approach that allows convenient design retrieval on the one hand and process-planning automation on the other. Our work is based on the assumption that form features are recognizable and extractable from the CAD model by current feature-recognition, feature extraction and feature-based-design approaches. The coding procedure is applicable to the boundary representation of the object and its extracted form features.

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