f4004a04 Phy Term Paper.

8/22/2019 f4004a04 Phy Term Paper.

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TERM PAPER

ON

Computer aided design

NAME - SAURABH KUMAR

SECTION - F4004

ROLL NO - RF400404

REG. NO - 11000520

SUBJECT - PHY 101

SUBMITTED TO - MISS. SANDEEP KAUR

ACKNOWLEDGEMENT


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I take this opportunity to present my votes of thanks to all

those guidepost who really acted as lightening pillars to

enlighten my way throughout this project that has led tosuccessful and satisfactory completion of this study.

. I am highly thankful to my mechanics lecturer Miss

SANDEEP KAUR for her active support, valuable time and

advice, whole-hearted guidance, sincere cooperation and

pains-taking involvement during the study and in completing

the assignment of preparing the said project within the time

stipulated.

Lastly, I am thankful to all those, particularly the various

friends , who have been instrumental in creating proper,

healthy and conductive environment and including new and

fresh innovative ideas for us during the project, their help, it

would have been extremely difficult for me to prepare the

project in a time bound framework.

Name SAURABH KUMAR

Regd.No-

11000520

Rollno. - RF4004A04

SECTION- F4004


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INTRODUCTION :-

A CAD system is a combination of hardware and software that

create and store drawings, which can be viewed, printed, or

updated as required. CAD systems have evolved from the days

of their introduction in the 1950s. From being able to merely

develop flat two-dimensional drawings, they can now create

dynamic and mathematically enriched three-dimensional (3D)

models. These systems enable companies to produce cost-

effective and precise illustrations of physical systems, ranging

from furniture to airplanes.

A CAD system stores graphical elements, such as lines, arcs, coordinates,dimensions and text in a database. These can be manipulated in many ways,

allowing for speedy production of 2D and 3D images and providing users with

graphic engineeringcapabilities. Additionally, CAD is integrated with various

other systems, such as Computer Aided Manufacturing (CAM) tools that assist

business units automate and increase their productivity. Thus, by using CAD,

organizations can proactively customize and manufacture their creations and

gain increased competitive advantage.

Companies, like people, use images and pictures to make a point whether it is

to explain design or market products. For example manufacturing units largely

depend on drawings to illustrate their products during the design phases.

Organizations inhabiting the design space such as those in media, fashion,

architecture, rely heavily on graphical communication. To enable accurate

product illustrations and graphics, technology providers offer a range of

Computer Aided Design (CAD) systems.


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COMPUTER AIDED DESIGN AND DRAFTING

(LOILET COLLEGE INTERIOR)

EVOLUTION OF CAD :-The late 1950s saw the introduction of the first generation of CAD systems.

They were primarily utilized in the Aviation, Automobile and Electronics

Industries, and helped companies in these areas engineer their products. These

CAD systems ran off specially designed computers and this was a practice

that was prevalent till the mid 1980s High cost, coupled with slow and complex

usage restricted their market. Since then, technology advancements have caused

CAD systems to evolve as cost-effective and efficient applications that run on

general-purpose workstations and personal computers. Today, they are being

used extensively in varied businesses.

In the past four decades, the evolution of CAD has undergone the following

major phases:

From paper-based design to 2D electronic models

From 2D to 3D modeling


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CAD offshoots

FROM PAPER-BASED DESIGN TO 2D

ELECTRONIC MODELS:-

Prior to the introduction of CAD, organizations relied on conventional hand

drawn illustrations to represent a given product. These took hours to prepare,

and several rounds of modifications before the approval of the final design.

Storage of graphical data and modifying them was a complex procedure that

demanded significant time and human resources. Moreover, precise

representation of complicated parts was a major issue. Any flaw in the design

could result in the stalling, modification and repetition of the entire design

process. These drawbacks limited the scope and speed of business operations.

Advances in technology especially the introduction of cost effective, high

powered computing at the desktop level allowed technology providers to meet

the demand for Computer Aided Design.

The first generation of CAD was designed to electronically modify existing

drawings. A flying spot scanner converted microfilm data into a 2D electronic

model. Points in such illustrations existed in geometric X and Y-axis.

Advantages of First Generation

CAD Systems :-

From a business perspective a reliance on hand drawn illustrations did not allow

for a company to incorporate changes and customer feed back quickly into thedesign. As a result companies were not able to create products as per exact

client specifications.

On the other hand, the introduction of CAD allowed for the customization of the

design, which now could easily be modified as per client specifications. This

was made possible by allowing easy archival, storage and manipulation of

graphic elements. As a result, organizations could significantly reduce

development cycle time and offer greater customer involvement during the

product design phase. A research conducted by Thomas Kurlak. Merrill Lynch


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Capital Markets indicated that between 1973 and 1981, the CAD market grew

from under $25 million in annual sales to over $1 billion. Initial employers of

CAD systems used them to engineer their aircraft, automobile and electronic

products. These products were largely employed by the US Department of

Defense (DOD). In fact, DOD had a big hand in encouraging CAD in its initial

phase of development.

Limitations of First

Generation CAD Systems :-

The output of both paper drawings and first generation CAD specific standards.

Thus, these systems did not provide the flexibility to efficiently manipulate

dimensions, specifically depth.

Early CAD systems required specially developed hardware and software. With

high-costs of implementation and maintenance, their market was limited to

government sectors and large manufacturing units. Moreover, these systemswere complex to understand and operate leading to a higher learning curve.

Domain expertise was limited to a few people and the required skill-set to

operate them was scarce.

These shortcomings became challenges for the next generation of CAD

systems. Vendors worked towards making their CAD offerings cost-effective,

user-friendly and enriched with advanced functionality. Thus, with the

evolution of CAD, earlier limitations started to diminish. With increased market

acknowledgement, its domain expertise also raised.

A PERSON USING CAD:-


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FROM 2D TO 3D MODELING :-

Precise dimensions are important for accurate representation of complex

physical products. Initial CAD systems could not represent complicated 3D

geometry with a finite amount of 2D drawings. However, organizations felt the

need for advanced functionality to manipulate dimensions in their CAD

systems. This instigated the 2D to 3D evolution. A 3D illustration is

essentially a 2D diagram with a depth property that indicates where points in

the drawing exist on an imaginary Z-axis. Further technological advancements

resulted in lower cost of hardware and software, coupled with increased

computer processing power. These allowed vendors to offer cost-effective 3D

modeling capabilities in their CAD offerings.

Advantages of 3D Modeling :-

CAD systems with 3D modeling capabilities assisted in precise representation

of complicated physical products and their parts., Where 2D digital drawings

slowed the design process due to dimension issues, 3D diagrams savedconsiderable cycle time.

3D modeling also made complicated design issues transparent. This allowed

users to optimize models in initial design phases, further saving development

time. Moreover, it allowed assembly and manufacturing constraints to be

studied while designing products. This, in turn, ensured efficient production.


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3D digital objects are exact virtual replicas of the product under

consideration. CAD systems with 3D modeling features provide the

functionality for viewing a product model from various angles, cross sections,

dimensions, and details.

New Generation of CAD Systems :-

Initial CAD systems were specially constructed computers with a restricted

market. Today, they have evolved as user-friendly, cost-effective, packaged and

customized software applications that can run on nearly all computer systems.

At most, they need a high-quality graphics monitor; a mouse, light pen, or

digitizing tablet for drawing; and a special printer or plotter for printing designspecifications. For supporting advanced 3D solid modeling, graphics hardware,

such as a graphic chip and card, may be required.

CAD systems are freely available in the market and are extensively used by

various businesses. Their applications can range from designing clasps to

engineering airplanes. Some popular systems are listed below:

1.) AutoDesk Inventor

2.) AutoDesk AutoCAD

3.) Dassault CATIA

4.) PTC Pro/Engineer

5.) Bentley MicroStation

6.) Discreet Studio Max

7.) Alias|Wavefront Studio

8.) ROLE OF CAD/CAM

CAD systems have fundamentally changed the way product design is done.

They are increasingly being employed by varied enterprises to gain competitive

advantage. Additionally, CAD-powered systems, such as CAD/CAM, allow

manufacturers to achieve greater productivity in less time. The role and scope of

CAD in businesses is highlighted below.

9.)


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CAD is used primarily in the engineering and manufacturing sectors. It is used

to design and engineer aircraft, automobiles, machinery, spare parts and other

such products. Various CAD packages are available that help fashion houses,

media companies, architecture firms, interior designers, and other organizations

requiring heavy graphic support, streamline their operations. Modern CAD

systems are cost-effective and user-friendly. This has helped expanded their

market. These systems are increasingly being used by various large, medium

and small businesses.

10.)

International Data Corp and Document Management magazine estimate that

there are more than 8 billion drawings worldwide, of which fewer than 15

percent are developed using Computer Aided Design. This leaves an

astonishing 85 percent of drawings created and maintained in non-electronic

format, mainly paper-based engineering archives. Considering that each

successive stage in a product cycle-design, production and support services use

substantially more documentation, the benefits of integrating this information

grows exponentially. Since CAD systems can successfully achieve this, their

market potential is vast. According to a research conducted by Daratech, user

spending on mechanical CAD/CAM/CAE software and services touched $6.7

billion in 2001, with a growth rate of 11.4% over the previous year. Such

figures are expected to grow further in the coming years.

11.)

Today, the main emphasis on CAD is to be able to optimize not only early

sketched, product design modification and documentation, but also

manufacturing all by using a single tool. Modern high-end 3D CAD systems

aim to fulfill these requirements by providing all-in-one solutions. Recent

innovations in hardware and software have increased the scope of utilization of

CAD and CAD-based systems. They are increasingly being used to formulate

product manufacturing and management strategies. The total expenditure

worldwide on CAD related software and services, was as high as $17 billion in

2000 alone.

12.)

CAM demonstrates the latent drive towards computerization that is just now

touching manufacturing, where in other industries it has prevailed and matured.


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This has led to a concern amongst skilled workers that computers will replace

future generations of machinist as engineers become versed in CAM. At least in

the United States, there is a shortage of young, skilled machinists entering the

workforce able to perform at the extremes of manufacturing; high precision and

mass production.

3D VIEW OF A FACTORY :-

Types OF CAD :-There are several different types of CAD. Each of these different types of CAD

systems require the operator to think differently about how he or she will use

them and he or she must design their virtual components in a different manner

for each.

There are many producers of the lower-end 2D systems, including a number of

free and open source programs. These provide an approach to the drawing

process without all the fuss over scale and placement on the drawing sheet thataccompanied hand drafting, since these can be adjusted as required during the

creation of the final draft.

a.) 3D wireframe is basically an extension of 2D drafting. Each line has to be

manually inserted into the drawing. The final product has no mass properties

associated with it and cannot have features directly added to it, such as holes.

The operator approaches these in a similar fashion to the 2D systems, although


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many 3D systems allow using the wireframe model to make the final

engineering drawing views.

b.) 3D "dumb" solids (programs incorporating this technology include

AutoCAD) are created in a way analogous to manipulations of real worldobjects. Basic three-dimensional geometric forms (prisms, cylinders, spheres,

and so on) have solid volumes added or subtracted from them, as if assembling

or cutting real-world objects. Two-dimensional projected views can easily be

generated from the models. Basic 3D solids don't usually include tools to easily

allow motion of components, set limits to their motion, or identify interference

between components.

c.) 3D parametric solid modeling require the operator to use what is referred toas "design intent". The objects and features created are adjustable. Any future

modifications will be simple, difficult, or nearly impossible, depending on how

the original part was created. One must think of this as being a "perfect world"

representation of the component. If a feature was intended to be located from

the center of the part, the operator needs to locate it from the center of the

model, not, perhaps, from a more convenient edge or an arbitrary point, as he

could when using "dumb" solids. Parametric solids require the operator to

consider the consequences of his actions carefully.

Some software packages provide the ability to edit parametric and non-

parametric geometry without the need to understand or undo the design intent

history of the geometry by use of direct modeling functionality. This ability

may also include the additional ability to infer the correct relationships between

selected geometry (e.g., tangency, concentricity) which makes the editing

process less time and labor intensive while still freeing the engineer from the

burden of understanding the models design intent history. These kind of non

history based systems are called Explicit Modellers or Direct CAD Modelers.

The first Explicit Modeling system was introduced to the world at the end of

80's by Hewlett-Packard under the name SolidDesigner.

Draft views are able to be generated easily from the models. Assemblies usually

incorporate tools to represent the motions of components, set their limits, and

identify interference. The tool kits available for these systems are ever

increasing; including 3D piping and injection mold designing packages.

Applications of cad :-


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Computer-aided design (CAD), also known as computer-aided design and

drafting (CADD), is the use of computer technology for the process of design

and design-documentation. Computer Aided Drafting describes the process of

drafting with a computer. CADD software, or environments, provide the user

with input-tools for the purpose of streamlining design processes; drafting,

documentation, and manufacturing processes. CADD output is often in the form

of electronic files for print or machining operations. The development of

CADD-based software is in direct correlation with the processes it seeks to

economize; industry-based software (construction, manufacturing, etc.)

typically uses vector-based (linear) environments whereas graphic-based

software utilizes raster-based (pixelated) environments.

1.) 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.

2.) CAD is also widely used to produce computer animation for special effects

in movies, advertising and technical manuals. 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.

3.) CAD has been a major driving force for research in computationalgeometry, computer graphics (both hardware and software), and discrete

differential geometry

4.) CAD 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)

5.) CAD is mainly used for detailed engineering of 3D models and/or 2D

drawings of physical components, but it is also used throughout the engineeringprocess 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.

6.) CAD is one part of the whole Digital Product Development (DPD) activity

within the Product Lifecycle Management (PLM) process, and as such is used

together with other tools, which are either integrated modules or stand-alone

products, such as:

a.) Computer-aided engineering (CAE) and Finite element analysis (FEA)


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b.) Computer-aided manufacturing (CAM) including instructions to Computer

Numerical Control (CNC) machines

c.) Photo realistic rendering

d.) Document management and revision control using Product Data

Management (PDM).

Effects :-

Beginning in the 1980s Computer-Aided Design programs reduced the need of

draftsmen significantly, especially in small to mid-sized companies. Theiraffordability and ability to run on personal computers also allowed engineers to

do their own drafting work, eliminating the need for entire departments. In

today's world most, if not all, students in universities do not learn drafting

techniques because they are not required to do so. The days of mechanical

drawings are almost obsolete.[4] Universities such as New Jersey Institute of

Technology no longer require the use of protractors and compasses to create

mechanical drawings, instead there are several classes that focus on the use of

CAD software such as Pro Engineer or IDEAS-MS.

Another consequence had been that since the latest advances were often quite

expensive, small and even mid-size firms often could not compete against large

firms who could use their computational edge for competitive purposes.[citation

needed] Today, however, hardware and software costs have come down. Even

high-end packages work on less expensive platforms and some even support

multiple platforms. The costs associated with CAD implementation now are

more heavily weighted to the costs of training in the use of these high level

tools, the cost of integrating a CAD/CAM/CAE PLM using enterprise across

multi-CAD and multi-platform environments and the costs of modifying design

work flows to exploit the full advantage of CAD tools. CAD vendors have

effectively lowered these training costs. These methods can be split into three

categories:

Improved and simplified user interfaces. This includes the availability of role

specific tailorable user interfaces through which commands are presented to

users in a form appropriate to their function and expertise.


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Enhancements to application software. One such example is improved design-

in-context, through the ability to model/edit a design component from within the

context of a large, even multi-CAD, active digital mockup.

User oriented modeling options. This includes the ability to free the user fromthe need to understand the design intent history of a complex intelligent model

REFRENCES :-

www.wikipedia.com

www.sciencedirect.com

www.srikumar.com
http://www.wikipedia.com/http://www.sciencedirect.com/http://www.srikumar.com/http://www.wikipedia.com/http://www.sciencedirect.com/http://www.srikumar.com/

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