Solid modeling 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. Together, the principles of geometric and solid modeling form the foundation of 3D-computer-aided design and in general support the creation, visualization, animation and annotation of digital models of physical objects; the use of solid modeling techniques allows for the automation of several difficult engineering calculations that are carried out as a part of the design process. Simulation and verification of processes such as machining and assembly were one of the main catalysts for the development of solid modeling. More the range of supported manufacturing applications has been expanded to include sheet metal manufacturing, injection molding, pipe routing, etc. Beyond traditional manufacturing, solid modeling techniques serve as the foundation for rapid prototyping, digital data archival and reverse engineering by reconstructing solids from sampled points on physical objects, mechanical analysis using finite elements, motion planning and NC path verification and dynamic analysis of mechanisms, so on.
A central problem in all these applications is the ability to represent and manipulate three-dimensional geometry in a fashion, consistent with the physical behavior of real artifacts. Solid modeling research and development has addressed many of these issues, continues to be a central focus of computer-aided engineering; the notion of solid modeling as practised today relies on the specific need for informational completeness in mechanical geometric modeling systems, in the sense that any computer model should support all geometric queries that may be asked of its corresponding physical object. The requirement implicitly recognizes the possibility of several computer representations of the same physical object as long as any two such representations are consistent, it is impossible to computationally verify informational completeness of a representation unless the notion of a physical object is defined in terms of computable mathematical properties and independent of any particular representation.
Such reasoning led to the development of the modeling paradigm that has shaped the field of solid modeling as we know it today. All manufactured components have finite size and well behaved boundaries, so the focus was on mathematically modeling rigid parts made of homogeneous isotropic material that could be added or removed; these postulated properties can be translated into properties of subsets of three-dimensional Euclidean space. The two common approaches to define solidity rely on point-set topology and algebraic topology respectively. Both models specify how solids can be built from simple cells. According to the continuum point-set model of solidity, all the points of any X ⊂ ℝ3 can be classified according to their neighborhoods with respect to X as interior, exterior, or boundary points. Assuming ℝ3 is endowed with the typical Euclidean metric, a neighborhood of a point p ∈X takes the form of an open ball. For X to be considered solid, every neighborhood of any p ∈X must be three dimensional.
Dimensional homogeneity of neighborhoods is guaranteed for the class of closed regular sets, defined as sets equal to the closure of their interior. Any X ⊂ ℝ3 can be turned into a closed regular set or regularized by taking the closure of its interior, thus the modeling space of solids is mathematically defined to be the space of closed regular subsets of ℝ3. In addition, solids are required to be closed under the Boolean operations of set union and difference. Applying the standard Boolean operations to closed regular sets may not produce a closed regular set, but this problem can be solved by regularizing the result of applying the standard Boolean operations; the regularized set operations are denoted ∪∗, ∩∗, −∗. The combinatorial characterization of a set X ⊂ ℝ3 as a solid involves representing X as an orientable cell complex so that the cells provide finite spatial addresses for points in an otherwise innumerable continuum; the class of semi-analytic bounded subsets of Euclidean space is closed under Boolean operations and exhibits the additional property that every semi-analytic set can be stratified into a collection of disjoint cells of dimensions 0,1,2,3.
A triangulation of a semi-analytic set into a collection of points, line segments, triangular faces, tetrahedral elements is an example of a stratification, used. The combinatorial model of solidity is summarized by saying that in addition to being semi-analytic bounded subsets, solids are three-dimensional topological polyhedra three-dimensional orientable manifolds with boundary. In particular this implies the Euler characteristic of the combinatorial boundary of the polyhedron is 2; the combinatorial manifold model of solidity guarantees the boundary of a solid separates space into two components as a consequence of the Jordan-Brouwer theorem, thus eliminating sets with non-manifold neighborhoods that are deemed impossible to manufacture. The point-set and combinatorial models of solids are consistent with each other, can be used interchangeably, relying on continuum or combinatorial properties as needed, can be extended to n dimensions; the key property that facilitates this consistency is that the clas
In industry, product lifecycle management is the process of managing the entire lifecycle of a product from inception, through engineering design and manufacture, to service and disposal of manufactured products. PLM integrates people, data and business systems and provides a product information backbone for companies and their extended enterprise; the inspiration for the burgeoning business process now known as PLM came from American Motors Corporation. The automaker was looking for a way to speed up its product development process to compete better against its larger competitors in 1985, according to François Castaing, Vice President for Product Engineering and Development. Lacking the "massive budgets of General Motors and foreign competitors … AMC placed R&D emphasis on bolstering the product life cycle of its prime products." After introducing its compact Jeep Cherokee, the vehicle that launched the modern sport utility vehicle market, AMC began development of a new model, that came out as the Jeep Grand Cherokee.
The first part in its quest for faster product development was computer-aided design software system that made engineers more productive. The second part in this effort was the new communication system that allowed conflicts to be resolved faster, as well as reducing costly engineering changes because all drawings and documents were in a central database; the product data management was so effective that after AMC was purchased by Chrysler, the system was expanded throughout the enterprise connecting everyone involved in designing and building products. While an early adopter of PLM technology, Chrysler was able to become the auto industry's lowest-cost producer, recording development costs that were half of the industry average by the mid-1990s. During 1982-83, Rockwell International developed initial concepts of PDM and PLM for the B-1B bomber program; the system called Engineering Data System was augmented to interface with Computervision and CADAM systems to track part configurations and lifecycle of components and assemblies.
Computervison released implementing only the PDM aspects as the lifecycle model was specific to Rockwell and aerospace needs. PLM systems help organizations in coping with the increasing complexity and engineering challenges of developing new products for the global competitive markets. Product lifecycle management should be distinguished from'product life-cycle management'. PLM describes the engineering aspect of a product, from managing descriptions and properties of a product through its development and useful life. Product lifecycle management can be considered one of the four cornerstones of a manufacturing corporation's information technology structure. All companies need to manage communications and information with their customers, their suppliers and fulfillment, their resources within the enterprise and their product planning and development. One form of PLM is called people-centric PLM. While traditional PLM tools have been deployed only on release or during the release phase, people-centric PLM targets the design phase.
As of 2009, ICT development has allowed PLM to extend beyond traditional PLM and integrate sensor data and real time'lifecycle event data' into PLM, as well as allowing this information to be made available to different players in the total lifecycle of an individual product. This has resulted in the extension of PLM into closed-loop lifecycle management. Documented benefits of product lifecycle management include: Reduced time to market Increase full price sales Improved product quality and reliability Reduced prototyping costs More accurate and timely request for quote generation Ability to identify potential sales opportunities and revenue contributions Savings through the re-use of original data A framework for product optimization Reduced waste Savings through the complete integration of engineering workflows Documentation that can assist in proving compliance for RoHS or Title 21 CFR Part 11 Ability to provide contract manufacturers with access to a centralized product record Seasonal fluctuation management Improved forecasting to reduce material costs Maximize supply chain collaboration Within PLM there are five primary areas.
An important aspect for life cycle management is a subset within Systems Engineering called Reliability Engineering. Product and portfolio m² is focused on managing resource allocation, tracking progress, plan for new product development projects that are in process. Portfolio management is a tool that assists management in tracking progress on new products and making trade-off decisions when allocating scarce resources. Product design is the process of creating a new product to be sold by a business to its customers. Manufacturing process management is a collection of technologies and methods used to define how products are to be manufactured. Product data management is focused on capturing and maintaining information on products and/or services through their development and useful life. Change management is an important part of PDM/PLM. Note: While application software is not required for PLM processes, the business complexity and rate of change requires organizations execute as as possible.
The core of PLM (product lif
Constraint (computer-aided design)
In engineering design in the use of computer-aided drafting and design, in the creation of 3D assemblies and multibody systems, the plural term "constraints" refers to demarcations of geometrical characteristics between two or more entities or solid modeling bodies. In addition, 2D sketches -including the ones used to create extrusions and solid bodies- can be constrained. There are several constraints that may be applied between the entities or bodies depending much on their actual natural geometry. A constraint on two lines may be added so these are equal in length. Moreover, a solid model can be set to be locked or fixed in space. Depending on the program, the terminology used in the application may differ; the purpose of constraints in a design is to control and limit the behavior of the entities and bodies in relation to another entity, plane or body. Effective constraints or mates between two or more bodies may exist at the assembly level of these or between two or more entities in defining a sketch, but adding conflicting, unnecessary or redundant constraints may result in an overdefined sketch and an error message.
Ideally, a rod will need to be concentric to a hole drilled through the plate where it will be inserted, so the constraint "concentric" guarantees that the diameter of the rod and the diameter of the hole maintain a common centerline, thus "locking" the manner the rod relates to the hole in the plate, this means that the rod could still slide on either direction since the position of its ends has not been limited. Constraint Preliminary design & detailed design Parametric modeling Geometric constraint solving Introducing AutoCAD 2010 and AutoCAD LT 2010, by George Omura. 2009. Edition. Wiley Publishing, Inc. Indianapolis, Indiana. ISBN 978-0-470-43867-1 Hard Cover. Autodesk® Inventor® 2011 Essentials Plus, by Daniel T. Banach. 2011. Printed in the United States of America. ISBN 978-1-1111-3527-0. New York
Visualization or visualisation is any technique for creating images, diagrams, or animations to communicate a message. Visualization through visual imagery has been an effective way to communicate both abstract and concrete ideas since the dawn of humanity. Examples from history include cave paintings, Egyptian hieroglyphs, Greek geometry, Leonardo da Vinci's revolutionary methods of technical drawing for engineering and scientific purposes. Visualization today has ever-expanding applications in science, engineering, interactive multimedia, etc. Typical of a visualization application is the field of computer graphics; the invention of computer graphics may be the most important development in visualization since the invention of central perspective in the Renaissance period. The development of animation helped advance visualization; the use of visualization to present information is not a new phenomenon. It has been used in maps, scientific drawings, data plots for over a thousand years. Examples from cartography include Ptolemy's Geographia, a map of China, Minard's map of Napoleon's invasion of Russia a century and a half ago.
Most of the concepts learned in devising these images carry over in a straightforward manner to computer visualization. Edward Tufte has written three critically acclaimed books. Computer graphics has from its beginning been used to study scientific problems. However, in its early days the lack of graphics power limited its usefulness; the recent emphasis on visualization started in 1987 with the publication of Visualization in Scientific Computing, a special issue of Computer Graphics. Since there have been several conferences and workshops, co-sponsored by the IEEE Computer Society and ACM SIGGRAPH, devoted to the general topic, special areas in the field, for example volume visualization. Most people are familiar with the digital animations produced to present meteorological data during weather reports on television, though few can distinguish between those models of reality and the satellite photos that are shown on such programs. TV offers scientific visualizations when it shows computer drawn and animated reconstructions of road or airplane accidents.
Some of the most popular examples of scientific visualizations are computer-generated images that show real spacecraft in action, out in the void far beyond Earth, or on other planets. Dynamic forms of visualization, such as educational animation or timelines, have the potential to enhance learning about systems that change over time. Apart from the distinction between interactive visualizations and animation, the most useful categorization is between abstract and model-based scientific visualizations; the abstract visualizations show conceptual constructs in 2D or 3D. These generated shapes are arbitrary; the model-based visualizations either place overlays of data on real or digitally constructed images of reality or make a digital construction of a real object directly from the scientific data. Scientific visualization is done with specialized software, though there are a few exceptions, noted below; some of these specialized programs have been released as open source software, having often its origins in universities, within an academic environment where sharing software tools and giving access to the source code is common.
There are many proprietary software packages of scientific visualization tools. Models and frameworks for building visualizations include the data flow models popularized by systems such as AVS, IRIS Explorer, VTK toolkit, data state models in spreadsheet systems such as the Spreadsheet for Visualization and Spreadsheet for Images; as a subject in computer science, scientific visualization is the use of interactive, sensory representations visual, of abstract data to reinforce cognition, hypothesis building, reasoning. Data visualization is a related subcategory of visualization dealing with statistical graphics and geographic or spatial data, abstracted in schematic form. Scientific visualization is the transformation, selection, or representation of data from simulations or experiments, with an implicit or explicit geometric structure, to allow the exploration and understanding of the data. Scientific visualization focuses and emphasizes the representation of higher order data using graphics and animation techniques.
It is a important part of visualization and maybe the first one, as the visualization of experiments and phenomena is as old as science itself. Traditional areas of scientific visualization are flow visualization, medical visualization, astrophysical visualization, chemical visualization. There are several different techniques to visualize scientific data, with isosurface reconstruction and direct volume rendering being the more common. Educational visualization is using a simulation to create an image of something so it can be taught about; this is useful when teaching about a topic, difficult to otherwise see, for example, atomic structure, because atoms are far too small to be studied without expensive and difficult to use scientific equipment. Information visualization concentrates on the use of computer-supported tools to explore large amount of abstract data; the term "information visualization" was coined by the User Interface Research Group at Xerox PARC and included Jock Mackinlay. Practical application of information visualization in computer programs involves selecting and representing abstract data in a form that facilitates human interaction for exploration and understanding.
Collaborative product development
Collaborative product development is a business strategy, work process and collection of software applications that facilitates different organizations to work together on the development of a product. It is known as collaborative product definition management. Collaborative Product Development helps individual users and companies manage and view your CAD projects without the cost and complexity of purchasing an entire PDM or PLM solution. CPD comes in the form of a Software as a service delivery model, which allows for rapid iterations and little or no downloads and installs. What technology comes under this title does vary depending on whom one asks, it is accepted as not including CAD geometry tools, but does include data translation technology. General collaborative software such as email and chat is used within the CPD process. One important technology is application and desktop sharing, allowing one person to view what another person is doing on a remote machine. For CAD and product visualization applications an ‘appshare’ product that supports OpenGL graphics is required.
Another common application is Data sharing via Web based portals. With product data an important addition is the handling of high volumes of metadata. What techniques and technology is required depends on the level of collaboration being carried out and the commonality of the partner sites’ systems. Collaboration using PLM and CAx tools requires technology to support the needs of: People. Personnel of different disciplines and skill levels. Appropriate technologies are required to support collaboration across these boundaries. People Effective PLM collaboration will require the participation of people who do not have high level CAD skills; this requires improved user interfaces including tailorable user interfaces that can be tailored to the skill level and specialty of the user. Improved visualization capabilities those that provide a meaningful view of complex information such as the results of a fluid flow analysis will leverage the value of all participants in the collaboration process. Effective collaboration requires that a participant be freed from the burden of knowing the intent history imbedded within and constricting the use of parametric models.
Organizations Community collaboration requires that companies and customers share information in a secure environment, ensure compliance with enterprise and regulatory rules and enforce the process management rules of the community as well as the individual organizations. Data The most basic collaboration data need is the ability to operate in a MultiCAD environment; that is, only the beginning. Models from multiple CAD sources must be assembled into an active digital mockup allowing change and/or design in context. Product design is a iterative and interactive activity involving a group of designers who are geographically dispersed. A neutral modeling commands based method is proposed to construct a real-time collaborative product design platform within heterogeneous CAD systems. Different from the visualization-based approaches, models can be constructed and modified synchronously from various sites in the proposed collaborative design environment. Based on a translation mechanism between system modeling operations and neutral modeling commands, every operation given by a user on one site will be translated into a NMC and be sent to all the other sites through the network.
When the other sites receive this command, it is converted into corresponding SMOs on the local system. In this way, the real-time collaborative product design with heterogeneous CAD systems is achieved. If the collaborating parties have the same PDM and CAD systems the task involves the direct access and transfer of data between sites; the PDM system will have data storage at more than one site for the large graphics files, file may be copied between sites, how they are synchronized being controlled by the server. For the management server and metadata there are a number of options. There could be a single server, accessed from all locations or multiple PDM servers that communicate with one another. In both cases the PDM software controls access for groups defining what data they can edit. With different CAD systems the approach varies depending on whether the ownership, therefore authorship, of components changes or not. If geometry only has to be viewed a Product visualization neutral file format can be used for tasks such as viewing, markup or multi-cad digital mock-up.
It maybe that authorship does not change but components from one group needs to be placed in the assembly of another group so that they can construct their parts, so called work in context. This requires transfer of geometry from one format to another by means of a visualization format or full data translation. Between some systems there is the possibility of ‘data interoperability’ where geometry from one format can be associatively copied to another. If the ownership of a particular file is being transfer full data translation is required using some form of CAD data exchange technology. For the translation process Product Data Quality checkers are employed to reduce problems in transferring the work. If different PDM/ED
Computer-aided design is the use of computers to aid in the creation, analysis, or optimization of a design. CAD software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, to create a database for manufacturing. CAD output is in the form of electronic files for print, machining, or other manufacturing operations; the term CADD is used. Its use in designing electronic systems is known as electronic design automation. In mechanical design it is known as mechanical design automation or computer-aided drafting, which includes the process of creating a technical drawing with the use of computer software. CAD software for mechanical design uses either vector-based graphics to depict the objects of traditional drafting, or may produce raster graphics showing the overall 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 and tolerances, according to application-specific conventions.
CAD may be used to design figures in two-dimensional space. CAD is an important industrial art extensively used in many applications, including automotive and aerospace industries and architectural design and many more. CAD is widely used to produce computer animation for special effects in movies and technical manuals called DCC digital content creation; the modern ubiquity and power of computers means that perfume bottles and shampoo dispensers are designed using techniques unheard of by engineers of the 1960s. Because of its enormous economic importance, CAD has been a major driving force for research in computational geometry, computer graphics, discrete differential geometry; the design of geometric models for object shapes, in particular, is called computer-aided geometric design. Starting around the mid 1960s, with the IBM Drafting System, computer-aided design systems began to provide more capability than just an ability to reproduce manual drafting with electronic drafting, the cost-benefit for companies to switch to CAD became apparent.
The benefits of CAD systems over manual drafting are the capabilities one takes for granted from computer systems today. CAD provided the designer with the ability to perform engineering calculations. During this transition, calculations were still performed either by hand or by those individuals who could run computer programs. CAD was a revolutionary change in the engineering industry, where draftsmen and engineering roles begin to merge, it did not eliminate departments, as much as it merged departments and empowered draftsman and engineers. CAD is an example of the pervasive effect. Current computer-aided design software packages range from 2D vector-based drafting systems to 3D solid and surface modelers. Modern CAD packages can frequently allow rotations in three dimensions, allowing viewing of a designed object from any desired angle from the inside looking out; some CAD software is capable of dynamic mathematical modeling. CAD technology is used in the design of tools and machinery and in the drafting and design of all types of buildings, from small residential types to the largest commercial and industrial structures.
CAD is used for detailed engineering of 3D models or 2D drawings of physical components, but it is used throughout the engineering process from conceptual design and layout of products, through strength and dynamic analysis of assemblies to definition of manufacturing methods of components. It can be used to design objects such as jewelry, appliances, etc. Furthermore, many CAD applications now offer advanced rendering and animation capabilities so engineers can better visualize their product designs. 4D BIM is a type of virtual construction engineering simulation incorporating time or schedule related information for project management. CAD has become an important technology within the scope of computer-aided technologies, with benefits such as lower product development costs and a shortened design cycle. CAD enables designers to layout and develop work on screen, print it out and save it for future editing, saving time on their drawings. Computer-aided design is one of the many tools used by engineers and designers and is used in many ways depending on the profession of the user and the type of software in question.
CAD is one part of the whole digital product development activity within the product lifecycle management processes, as such is used together with other tools, which are either integrated modules or stand-alone products, such as: Computer-aided engineering and finite element analysis Computer-aided manufacturing including instructions to computer numerical control machines Photorealistic rendering and motion simulation. Document management and revision control using product data management. CAD is used for the accurate creation of photo simulations that are required in the preparation of environmental impact reports, in which computer-aided designs of intended buildings are superimposed into photographs of existing environments to represent what that locale will be like, where the proposed facilities are allowed to be built. Pote