About CAD Software

Computer-aided design (CAD) is the use of computers (or workstations) to aid in the creation, modification, 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, and to create a database for manufacturing. Designs made through CAD software are helpful in protecting products and inventions when used in patent applications. CAD output is often in the form of electronic files for print, machining, or other manufacturing operations. The term CADD (for computer aided design and drafting) is also used. Its use in designing electronic systems is known as electronic design automation (EDA). In mechanical design it is known as mechanical design automation (MDA) or computer-aided drafting (CAD), 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 also 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, 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. CAD is an important industrial art extensively used in many applications, including automotive, shipbuilding, and aerospace industries, industrial and architectural design, prosthetics, and many more. CAD is also widely used to produce computer animation for special effects in movies, advertising and technical manuals, often called DCC digital content creation. The modern ubiquity and power of computers means that even 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 (both hardware and software), and discrete differential geometry. The design of geometric models for object shapes, in particular, is occasionally called computer-aided geometric design (CAGD). History Of CAD Designers have used computers for calculations since their invention. Digital computers were used in power system analysis or optimization as early as proto-"Whirlwind" in 1949. Circuit design theory or power network methodology was algebraic, symbolic, and often vector-based. 1940s–1950s Between the mid-1940s and 1950s, various developments were made in computer software. Some of these developments include servo-motors controlled by generated pulse (1949), a digital computer with built-in operations to automatically coordinate transforms to compute radar related vectors (1951), and the graphic mathematical process of forming a shape with a digital machine tool (1952). In 1953, MIT researcher Douglas T. Ross saw the "interactive display equipment" being used by radar operators, believing it would be exactly what his SAGE-related data reduction group needed. Ross and the other researchers from the Massachusetts Institute of Technology Lincoln Laboratory were the sole users of the complex display systems installed for the pre-SAGE Cape Cod system. Ross claimed in an interview that they "used it for their own personal workstation."The designers of these early computers built utility programs to ensure programmers could debug software, using flowcharts on a display scope, with logical switches that could be opened and closed during the debugging session. They found that they could create electronic symbols and geometric figures to create simple circuit diagrams and flowcharts. These programs also enabled objects to be reproduced at will; it also was possible to change their orientation, linkage (flux, mechanical, lexical scoping), or scale. This presented numerous possibilities to them. Ross coined the term computer-aided design (CAD) in 1959. 1960s The invention of the 3D CAD/CAM is attributed to French engineer Pierre Bézier (Arts et Métiers ParisTech, Renault). Between 1966 and 1968, after his mathematical work concerning surfaces, he developed UNISURF to ease the design of parts and tools for the automotive industry. UNISURF then became the working base for the following generations of CAD software. In the 1960s, technological developments in the industries of aircraft, automotive, industrial control, and electronics provided advancements in the fields of three-dimensional surface construction, NC programming, and design analysis. Most of these developments were independent of one another and often not published until much later. Some of the mathematical description work on curves was developed in the early 1940s by Robert Issac Newton.In his 1957 novel The Door into Summer, Robert A. Heinlein hinted at the possibility of a robotic Drafting Dan. However, more substantial work on polynomial curves and sculptured surface was done by mathematician Paul de Casteljau from Citroen; Pierre Bézier from Renault; Steven Anson Coons from MIT; James Ferguson from Boeing; Carl de Boor, George David Birkhoff and Garibedian from GM in the 1960s; and W. Gordon and R. Riesenfeld from GM in the 1970s. The development of the SKETCHPAD system at MIT by Ivan Sutherland, who later created a graphics technology company with David Evans, was a turning point. The distinctive feature of SKETCHPAD was that it allowed the designer to interact with their computer graphically; the design can be fed into the computer by drawing on a CRT monitor with a light pen. In effect, this feature of SKETCHPAD was a prototype for a graphical user interface, an indispensable feature of modern CAD. In 1963, under doctoral adviser Claude Shannon, Sutherland presented his PhD thesis paper, Sketchpad: A Man-Machine Graphical Communication System, at a Joint Computer Conference. In his paper, he said:[13] For drawings where motion of the drawing or analysis of a drawn problem is of value to the user, Sketchpad excels. For highly repetitive drawings or drawings where accuracy is required, Sketchpad is sufficiently faster than conventional techniques to be worthwhile. For drawings which merely communicate with shops, it is probably better to use conventional paper and pencil. Over time, efforts would be directed toward the goal of having the designers' drawings communicate not just with shops, but also with the shop tool itself; however, it was a long time before this goal was achieved. The first commercial applications of CAD were in large companies within the automotive and aerospace industries, as well as in electronics. This was because only large corporations could afford the computers capable of performing the necessary calculations. Notable company projects included a joint project between Patrick J. Hanratty from GM and Sam Matsa, Doug Ross's MIT APT research assistant from IBM, to develop a prototype system for design engineers, DAC-1 (Design Augmented by Computer) 1964, Lockheed projects, Bell GRAPHIC 1, and Renault. One of the most influential events in the development of CAD was the founding of Manufacturing and Consulting Services Inc. (MCS) in 1971 by Patrick J. Hanratty,[14] who wrote the system Automated Drafting And Machining (ADAM), but more importantly supplied code to companies such as McDonnell Douglas (Unigraphics), Computervision (CADDS), Calma, Gerber, Autotrol, and Control Data. As computers became more affordable, the application of CAD gradually expanded into new areas. The development of CAD software for personal desktop computers was the impetus for almost universal application in all areas of construction. 1970s Other notable events in the 1960s and 1970s include the foundation of CAD systems United Computing, Intergraph, IBM, and Intergraph IGDS in 1974 (which led to Bentley Systems MicroStation in 1984), as well as the Applicon in 1969 and commercial CAD systems from Japanese manufacturers Seiko and Zuken during the 1970s. CAD implementations have evolved dramatically since this early development. Initially, with 3D in the 1970s, CAD was typically limited to producing drawings similar to hand-drafted drawings. Advances in programming and computer hardware,most notably solid modeling in the 1980s, have allowed more versatile applications of computers in design activities. 1990s Also important to the development of CAD was the development in the late 1980s and early 1990s of B-rep solid modeling kernels (engines for manipulating geometrically and topologically consistent 3D objects), Parasolid (ShapeData), and ACIS (Spatial Technology Inc.). These developments were inspired by the work of Ian Braid. This subsequently led to the release of mid-range packages such as SolidWorks and TriSpective (later known as IRONCAD) in 1995, Solid Edge (then Intergraph) in 1996, and Autodesk Inventor in 1999. An independent geometric modeling kernel has been evolving in Russia since the 1990s. 2000s Availability of free and open-source CAD software and high costs of advanced and 3D CAD software may restrain the growth of the CAD software market. Free and open-source CAD software packages include BRL-CAD developed for the US Army, LibreCAD, FreeCAD,and others. CAD software: 1963: Sketchpad 1968: UNISURF 1977: CATIA 1978: Unigraphics 1983: BRL-CAD[22] 2002: FreeCAD 2007: NX 1987: Pro/ENGINEER 2009: Creo 2011: LibreCAD Overview Of CAD Software 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 often takes for granted from computer systems today; automated generation of bills of materials, auto layout in integrated circuits, interference checking, and many others. Eventually, 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, designers, and engineering roles begin to merge. It did not eliminate departments as much as it merged departments and empowered draftsmen, designers, and engineers. CAD is an example of the pervasive effect computers were beginning to have on the industry. Current computer-aided design software packages range from 2D vector-based drafting systems to 3D solid and surface modelers. Modern CAD packages can also frequently allow rotations in three dimensions, allowing viewing of a designed object from any desired angle, even 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 (houses) to the largest commercial and industrial structures (hospitals and factories). CAD is mainly used for detailed engineering of 3D models or 2D drawings of physical components, but it is also 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 also be used to design objects such as jewelry, furniture, 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 especially important technology within the scope of computer-aided technologies, with benefits such as lower product development costs and a greatly 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. Originally software for CAD systems was developed with computer languages such as Fortran, ALGOL but with the advancement of object-oriented programming methods this has radically changed. Typical modern parametric feature-based modeler and freeform surface systems are built around a number of key C modules with their own APIs. A CAD system can be seen as built up from the interaction of a graphical user interface (GUI) with NURBS geometry or boundary representation (B-rep) data via a geometric modeling kernel. A geometry constraint engine may also be employed to manage the associative relationships between geometry, such as wireframe geometry in a sketch or components in an assembly. Unexpected capabilities of these associative relationships have led to a new form of prototyping called digital prototyping. In contrast to physical prototypes, which entail manufacturing time in the design. That said, CAD models can be generated by a computer after the physical prototype has been scanned using an industrial CT scanning machine. Depending on the nature of the business, digital or physical prototypes can be initially chosen according to specific needs. Today, CAD systems exist for all the major platforms (Windows, Linux, UNIX and Mac OS X); some packages support multiple platforms. Currently, no special hardware is required for most CAD software. However, some CAD systems can do graphically and computationally intensive tasks, so a modern graphics card, high speed (and possibly multiple) CPUs and large amounts of RAM may be recommended. The human-machine interface is generally via a computer mouse but can also be via a pen and digitizing graphics tablet. Manipulation of the view of the model on the screen is also sometimes done with the use of a Spacemouse/SpaceBall. Some systems also support stereoscopic glasses for viewing the 3D model. Technologies which in the past were limited to larger installations or specialist applications have become available to a wide group of users. These include the CAVE or HMDs and interactive devices like motion-sensing technology. Software CAD software enables engineers and architects to design, inspect and manage engineering projects within an integrated graphical user interface (GUI) on a personal computer system. Most applications support solid modeling with boundary representation (B-Rep) and NURBS geometry, and enable the same to be published in a variety of formats. A geometric modeling kernel is a software component that provides solid modeling and surface modeling features to CAD applications. Based on market statistics, commercial software from Autodesk, Dassault Systems, Siemens PLM Software, and PTC dominate the CAD industry. The following is a list of major CAD applications, grouped by usage statistics.