CAD Model Inspection Utility and Prototyping Framework Based on Opencascade S
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MECH TA Office
Course Syllabus MECH 6303, Computer Aided Design Course Information: MECH 6303.501, Class Number: 82090, 3 semester hours Fall 2015 Tuesday and Thursday: 5:30pm – 6:45pm Lecture Room: CN 1.304 Starts: August 24, 2015 Ends: December 9, 2015 Professor Contact Information: Arif S. Malik, Ph.D Office Phone: 972-883-4550 Office: ECSN 3.208 Office Hours: Tuesday and Thursday 2–3pm Email: [email protected] TA: Suresh Ravinath [email protected] Office Hours: Tuesday and Thursday: 2:30–3:30pm (or by appointment) Office: MECH TA office Description: This course provides an introduction to design principles and methodologies for geometrical modeling, curve and surface fitting in an automated environment, CAD/CAM simulation of manufacturing, and computer-aided solid modeling including theoretical framework and applications using commercial CAD packages/programming languages. Projects involve CAD concepts to solve advanced engineering problems. The course is taught by lectures, tutorials, and presentations. Students are responsible to use the CAD lab for homework which is assigned on a regular basis. Students are required to propose project topics and present part/assembly and analysis during the last week of the class. These projects are discussed in class with sample project and posted in eLearning. Course Pre-requisites co-requisites and/or restrictions: Prerequisite: MECH 3305 Computer Aided Design or equivalent (3 undergraduate semester hours) Course Learning Outcome (CLO): 1) Fundamental understanding of CAD/CAM system including the principles and practice of computer aided solid modeling and its applications to manufacturing. 2) Be able to effectively use commercial CAD software (mainly SolidWorks and ProE/Creo). -
A Three-Dimensional Finite Element Mesh Generator with Built-In Pre- and Post-Processing Facilities
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING Int. J. Numer. Meth. Engng 2009; 0:1{24 Prepared using nmeauth.cls [Version: 2002/09/18 v2.02] This is a preprint of an article accepted for publication in the International Journal for Numerical Methods in Engineering, Copyright c 2009 John Wiley & Sons, Ltd. Gmsh: a three-dimensional finite element mesh generator with built-in pre- and post-processing facilities Christophe Geuzaine1, Jean-Fran¸cois Remacle2∗ 1 Universit´ede Li`ege,Department of Electrical Engineering And Computer Science, Montefiore Institute, Li`ege, Belgium. 2 Universite´ catholique de Louvain, Institute for Mechanical, Materials and Civil Engineering, Louvain-la-Neuve, Belgium SUMMARY Gmsh is an open-source three-dimensional finite element grid generator with a build-in CAD engine and post-processor. Its design goal is to provide a fast, light and user-friendly meshing tool with parametric input and advanced visualization capabilities. This paper presents the overall philosophy, the main design choices and some of the original algorithms implemented in Gmsh. Copyright c 2009 John Wiley & Sons, Ltd. key words: Computer Aided Design, Mesh generation, Post-Processing, Finite Element Method, Open Source Software 1. Introduction When we started the Gmsh project in the summer of 1996, our goal was to develop a fast, light and user-friendly interactive software tool to easily create geometries and meshes that could be used in our three-dimensional finite element solvers [8], and then visualize and export the computational results with maximum flexibility. At the time, no open-source software combining a CAD engine, a mesh generator and a post-processor was available: the existing integrated tools were expensive commercial packages [41], and the freeware or shareware tools were limited to either CAD [29], two-dimensional mesh generation [44], three-dimensional mesh generation [53, 21, 30], or post-processing [31]. -
Chapter 2 Principles of Geometric Modeling
In: Borrmann, A.; König, M.; Koch, C.; Beetz, J. (Eds): Building Information Modeling - Technology Foundations and Industry Practice, Springer, 2018, DOI: 10.1007/978-3-319-92862-3 Chapter 2 Principles of Geometric Modeling Andre´ Borrmann and Volker Berkhan Abstract The three-dimensional geometry of a building is a vital prerequisite for Building Information Modeling. This chapter examines the principles involved in representing geometry with a computer. It details explicit and implicit approaches to describing volumetric models as well as the basic principles of parametric modeling for creating flexible, adaptable models. The chapter concludes with an examination of freeform curves and surfaces and their underlying mathematical description. 2.1 Geometric modeling in the context of BIM A Building Information Model contains all the relevant information needed for the planning, construction and operation of a building. The three-dimensional descrip- tion of the geometry of a building is one of the most important aspects without which many BIM applications would not be possible. The availability of a model in three dimensions offers significant advantages over conventionally drawn plans: • The planning and construction of the building can be undertaken using a 3D model rather than separate plans and sections. Drawings are then generated from the 3D model, ensuring that the separate drawings always correspond and remain consistent with one another. This almost entirely eradicates a common source of errors, especially when alterations are made to the plans. But a three-dimensional geometric model on its own is not sufficient for generating plans that conform Andre´ Borrmann Technical University of Munich, Chair of Computational Modeling and Simulation, Arcisstr. -
What Direct Modeling Means for CAD Educators
Paper ID #16208 New Directions in Solid Modeling - What Direct Modeling Means for CAD Educators Holly K. Ault Ph.D., Worcester Polytechnic Institute Holly K. Ault is an associate professor of mechanical engineering at Worcester Polytechnic Institute. She serves as director of the Melbourne (Australia) Project Center and co-director of the Assistive Technol- ogy Resource Center. She received her B.S. in chemistry, and M.S. and Ph.D. degrees in mechanical engineering from WPI in 1974, 1983 and 1988 respectively. Professor Ault has advised off-campus project students in London, Copenhagen, Stockholm, Windhoek (Namibia), San Jose (Costa Rica), Washington, D.C., Boston, Modesto (Calif.), and Melbourne. In the fall of 2001, she was invited as the Lise Meitner Visiting Professor, department of design sciences, Lund Technical University, Lund, Sweden. Prior to teaching at WPI, she worked as a manufacturing engineer for the Norton Company in Worcester, Mass., and product-development engineer for the Olin Corporation in East Alton, Ill. Professor Ault’s primary teaching responsibilities include undergraduate- and graduate-level courses in computer-aided design, mechanical design, and rehabilitation engineering. Her research interests include computer-aided mechanical design, geometric modeling, kinematics, machine design, rehabilitation engi- neering, and assistive technology. She is a member of ASME, ASEE, ISGG and Tau Beta Pi. Mr. Arnold D. Phillips Jr., Worcester Polytechnic Institute c American Society for Engineering Education, 2016 New Directions in Solid Modeling – What Direct Modeling Means for CAD Educators Abstract Direct modeling is a little known CAD technology that has been around for many years. It uses direct manipulation of the geometry to effect changes in the part model, and is based on a boundary representation database. -
Partial Entity Structure: a Compact Non-Manifold Boundary
Partial Entity Structure: A Compact Non-Manifold Boundary Representation Based on Partial Topological Entities Sang Hun Lee Kunwoo Lee Graduate School of Automotive Engineering School of Mechanical and Aerospace Engineering Kookmin University, Korea Seoul National University, Korea +82-2-910-4835 +82-2-880-7141 shlee@kookmin,ac.kr [email protected] ABSTRACT 1. INTRODUCTION Non-manifold boundary representations have gained a great deal As a key element in CAD/CAM applications, geometric modeling of popularity in recent years and various representation schemes systems have evolved to widen their representation domains from have been proposed because they allow an even wider range of wireframes to surfaces, to solids, and finally to non-manifold objects for various applications than conventional manifold objects. Unlike previous geometric modelers, the non-manifold representations. However, since these schemes are mainly modeler allows any combination of wireframe, surface, solid, and interested in describing sufficient adjacency relationships of cellular models to be represented and manipulated in a unified topological entities, the models represented in these schemes topological representation. This characteristic provides many occupy too much storage space redundantly although they are advantages over conventional modelers as follows: very efficient in answering queries on topological adjacency • The non-manifold modeler can provide an integrated relationships. Storage requirement can arise as a crucial problem environment for the product development process, as the non- in models in which topological data is more dominant than manifold topological representation can represent different geometric data, such as tessellated or mesh models. models required in various stages of product development; To solve this problem, in this paper, we propose a compact conceptual design, final design, analysis, and manufacture [5, non-manifold boundary representation, called the partial entity 30]. -
CAD -- Computer Aided Design
Computer-aided design “CAD” and “CADD” redirect here. For other uses, see CAD (disambiguation) and CADD (disambiguation). Computer-aided design (CAD) is the use of computer CAD rendering of Sialk ziggurat based on archeological evidence Example: 2D CAD drawing or computer-aided drafting (CAD), which includes the process of creating a technical drawing with the use of computer software.[4] CAD software for mechanical design uses either vector- based graphics to depict the objects of traditional draft- ing, or may also produce raster graphics showing the over- all appearance of designed objects. However, it involves more than just shapes. As in the manual drafting of technical and engineering drawings, the output of CAD must convey information, such as materials, processes, dimensions, and tolerances, according to application- specific conventions. CAD may be used to design curves and figures in two- dimensional (2D) space; or curves, surfaces, and solids in three-dimensional (3D) space.[5] CAD is an important industrial art extensively used in many applications, including automotive, shipbuilding, and aerospace industries, industrial and architectural de- Example: 3D CAD model sign, prosthetics, and many more. CAD is also widely used to produce computer animation for special effects systems to aid in the creation, modification, analysis, or in movies, advertising and technical manuals, often called optimization of a design.[1] CAD software is used to in- DCC digital content creation. The modern ubiquity and crease the productivity of the designer, improve the qual- power of computers means that even perfume bottles ity of design, improve communications through docu- and shampoo dispensers are designed using techniques mentation, and to create a database for manufacturing.[2] unheard of by engineers of the 1960s. -
Geometry Data in Databases
4. Product Data 4.1 Geometrical Data Requirements and Methods to Manage Geometrical Data for Engineering Applications Overview • Geometric Modeling – Applications – Historical roots of Technical Modeling • Overview of Geometrical Models – Criteria – Wire-frame Models – CSG – Voxel/Octrees – Triangle Meshes (Polygon Meshes) – B-Rep • The Boundary Representation-Model – Basics – Primitives and Basic Data Structures – Modeling Kernels and File Formats – B-REP Data in Databases Schallehn: Data Management for Engineering Applications Historical Roots of Technical Modeling • Historical roots date back more than 2000 years – Sketches and informal drawings used in ancient Egypt and Greece (Euclid, 300BC) to medieval times – Move from agricultural to industrial age increased importance of sharing information for technical development and documentation – Around the 19th century patents (protection of intellectual property) required formalization of technical • Manual Technical Drawing on paper standard way for technical modeling until the 1980s – Formalized process with commonly used conventions for representing 3D geometries represents “visual language” – Projection methods (orthogonal, parallel, perspective) to map 3D geometries to 2D – Data representing concrete measures with special syntax as dimension values or parameters and legends • First Computer Aided Design (CAD) developed in the 1960’s – Became industrial practice in the 1980s – Required digital representation of geometries Schallehn: Data Management for Engineering Applications Historical -
Viewing Technologies for CAD Models
NISTIR 6966 Viewing Technologies for CAD Models Michelle Potts Steves Simon Frechette Manufacturing Systems Integration Division Manufacturing Engineering Laboratory February 2003 U.S. Department of Commerce Donald L. Evans, Secretary Technology Administration Phillip J. Bond, Under Secretary for Technology National Institute of Standards and Technology Arden L. Bement, Jr., Director Abstract This report describes Computer-Aided Design (CAD) model-viewing technologies1 used to support CAD-model review and analysis. CAD model viewers are tools that allow engineers and other users to view CAD models from distributed locations, often using lightweight viewing applications, often supporting multiple CAD formats. These tools are typically less expensive, faster, and simpler to use than native CAD systems for model review. These features are especially important for small and medium-sized enterprises that can not typically support multiple native CAD systems. Additionally, considerations when choosing a viewing technology are described, as well as, popular CAD-model file formats that viewing technologies can import. Introduction Visualization solutions offer the possibility of expanding engineering data review and collaboration to the extended enterprise. These tools allow engineers and others involved in product development and review to view 3-dimensional (3D) models from distributed locations, often using lightweight viewing applications or a standard Web browser. Visualization solutions are also useful when multiple CAD systems are used throughout an organization, because many viewers support multiple CAD formats. Viewers allow every authorized member in the organization to deal with heterogeneity and visualizing designs from a variety of formats without running full-function CAD systems. Some viewers can enable design review meetings over the Internet by allowing project members to view and analyze a model concurrently while shifting control between members. -
57 SOLID MODELING Christoph M
57 SOLID MODELING Christoph M. Hoffmann and Vadim Shapiro INTRODUCTION The objective of solid modeling is to represent, manipulate, and reason about the 3D shape of solid physical objects, by computer. As an application-oriented field, the scope of solid modeling, as well as the rel- ative emphasis on its parts, change over time. Since its inception, [RV82, Bra75], in the 1970s, the focus on modeling shape alone has continued to expand to integrate widening domains of physical properties. Monographs of the subject appeared in the late 1980s and include [Chi88, Hof89, M¨an88]. The expansion was and contin- ues to be driven by major applications that include manufacturing, architecture, construction, computer vision, materials science, medicine, biological engineering, graphics, and virtual reality. With the integration of new applications, and with the availability of inexpensive, powerful computing platforms, the relative impor- tance of specific shape representations can change. Along with such shifts, new modeling and analysis techniques are added. As a result, the field draws on very diverse technologies, including numerical analysis, symbolic algebraic computation, approximation theory, point set and algebraic topology, differential geometry, alge- braic geometry, and computational geometry. In this chapter, we first review the major representations of solids in Sec- tion 57.1. They include constructive solid geometry, boundary representation, spatial subdivisions of various types, and medial surface representations. With changing scope and focus, different representations enter and exit center stage. For instance, polygonal meshes and voxel-based representations became relatively marginal in the late 1990s, only to gain renewed interest and importance recently with the advent of 3D printing, because they allow representing a structured inte- rior of modeled shapes. -
Solid Modelling in Nebem
Solid Modelling in neBEM SINP, Kolkata group Applied Nuclear Physics Division Saha Institute of Nuclear Physics Bidhannagar, Kolkata, WB, India 10th RD51 Collaboration meeting Stony Brook University from 30 September 2012 to 05 October 2012 Outline ● A solid modeller ● Earlier status ● Various attempts ● Proposed approach ● Present status ● Future plans October 4, 2012 10th RD51 Collaboration Meeting 2 Solid modelling (wikipedia) ● Solid modeling (or modelling) is a consistent set of principles for mathematical and computer modeling of three- dimensional solids. ● Solid modeling is distinguished from related areas of geometric modeling and computer graphics by its emphasis on physical fidelity. ● The principles of geometric and solid modeling form the foundation of computer-aided design and in general support the creation, exchange, visualization, animation, interrogation, and annotation of digital models of physical objects. ● Solid modeling research and development has effectively addressed many of these issues, and continues to be a central focus of computer-aided engineering. October 4, 2012 10th RD51 Collaboration Meeting 3 Solid Modelling ● Constructive solid geometry (CSG), sometimes referred to as combinatorial solid geometry, is one of the two major types of Solid modelling. In a CSG system, complex objects are built by combining simpler objects, with primitive solids as the basic building blocks. The combinations make use of boolean operations, and the resulting objects are stored as trees. ● Boundary Representation (BREP) is the other of the two major types of solid modelling. BREP objects are built by describing the entire enclosing surface of an object. This will typically involve a variety of surface types including, for example, planar, cylindrical, NURB, and spherical surfaces. -
Hacking BRL-CAD
Tutorial Series Volume V Hacking BRL-CAD BRL-CAD Version 7.24.1 Approved for public release; distribution is unlimited. HACKING BRL-CAD Sean Morrison Eric Edwards Harmanpreet Singh Check Issac Clifford Yapp Scott Nesbitt HACKING BRL-CAD by Sean Morrison, Eric Edwards, Harmanpreet Singh, Check , Issac , Clifford Yapp, and Scott Nesbitt Table of Contents 1. ..................................................................................................................................... 1 iii iv Getting Started A Call to Arms Feature Overview Developers Working with Our Code What Code to Work On Contributing Code Documenters Working with Our Documentation Types of Documentation We Maintain What Documentation to Work On Contributing Documentation Other Contributors You Can Help Too Appendix: Resources and Examples Further References and Resources Doc Template: New MGED Command Code Example: Shooting Rays Code Example: Walking Geometry Code Example: Command Plugin Code Example: Root Solving A Call to Arms (and Contributors) "The future exists first in the imagination, then in the will, then in reality." - Mike Muuss Welcome to BRL-CAD! Whether you are a developer, documenter, graphic artist, academic, or someone who just wants to be involved in a unique open source project, BRL-CAD has a place for you. Our contributors come from all over the world and use their diverse backgrounds and talents to help maintain and enhance one of the oldest computer-aided design (CAD) packages used in government and industry today. What is BRL-CAD? BRL-CAD