Introduction - Computer Aided Design in Mechanical Engineering Notes | EduRev

: Introduction - Computer Aided Design in Mechanical Engineering Notes | EduRev

 Page 1


Chapter1 Introduction 
CHAPTER 1 
 
 
 
 
INTRODUCTION 
 
 
 
 
 
 
 
 
1.1 Introduction 
 
In general, a Computer Aided Design (CAD) package has three components: a) Design, 
b) Analysis, and c) Visualization, as shown in the sketch. A brief description of these 
components follows. 
 
a) Design: Design refers to geometric modeling, i.e., 2-D and 3-D modeling, including, 
drafting, part creation, creation of drawings with various views of the part, assemblies 
of the parts, etc.  
b) Analysis: Analysis refers to finite element analysis, optimization, and other number 
crunching engineering analyses. In general, a geometric model is first created and 
then the model is analyzed for loads, stresses, moment of inertia, and volume, etc. 
c) Visualization: Visualization refers to computer graphics, which includes: rendering a 
model, creation of pie charts, contour plots, shading a model, sizing, animation, etc. 
 
 
 
 
 
 
 
      Design     Analysis 
            
               
          
                                Visualization 
 
 
     
                           Components of Computer Aided Design 
 
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-1 
Page 2


Chapter1 Introduction 
CHAPTER 1 
 
 
 
 
INTRODUCTION 
 
 
 
 
 
 
 
 
1.1 Introduction 
 
In general, a Computer Aided Design (CAD) package has three components: a) Design, 
b) Analysis, and c) Visualization, as shown in the sketch. A brief description of these 
components follows. 
 
a) Design: Design refers to geometric modeling, i.e., 2-D and 3-D modeling, including, 
drafting, part creation, creation of drawings with various views of the part, assemblies 
of the parts, etc.  
b) Analysis: Analysis refers to finite element analysis, optimization, and other number 
crunching engineering analyses. In general, a geometric model is first created and 
then the model is analyzed for loads, stresses, moment of inertia, and volume, etc. 
c) Visualization: Visualization refers to computer graphics, which includes: rendering a 
model, creation of pie charts, contour plots, shading a model, sizing, animation, etc. 
 
 
 
 
 
 
 
      Design     Analysis 
            
               
          
                                Visualization 
 
 
     
                           Components of Computer Aided Design 
 
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-1 
Chapter1 Introduction 
 
Each of these three areas has been extensively developed in the last 30 years. Several 
books are written on each of these subjects and courses are available through the 
academic institutions and the industry. 
 
Most commercial CAD packages (software) consist of only a single component: design 
or analysis or visualization. However, a few of the vendors have developed an integrated 
package that includes not only these three areas, but also includes the manufacturing 
software (CAM). Due to the large storage requirement, integrated packages use either an 
UNIX workstation or a mainframe platform, and not the popular PC platform. With the 
improvement in PC computing speed, it’s only a matter of time before we see an 
integrated package run on a PC. CAD has revolutionized the modern engineering 
practice; small and large companies use it alike, spending several billion dollars for the 
initial purchase or lease alone. CAD related jobs are high in demand and the new 
graduates have advantage over their senior colleagues, as they are more up to date and 
more productive. 
 
In this course, we will limit our coverage to the design only. Those of you interested in 
analysis area, look into the course ME 160 – Introduction to Finite Element Analysis.  
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-2 
Page 3


Chapter1 Introduction 
CHAPTER 1 
 
 
 
 
INTRODUCTION 
 
 
 
 
 
 
 
 
1.1 Introduction 
 
In general, a Computer Aided Design (CAD) package has three components: a) Design, 
b) Analysis, and c) Visualization, as shown in the sketch. A brief description of these 
components follows. 
 
a) Design: Design refers to geometric modeling, i.e., 2-D and 3-D modeling, including, 
drafting, part creation, creation of drawings with various views of the part, assemblies 
of the parts, etc.  
b) Analysis: Analysis refers to finite element analysis, optimization, and other number 
crunching engineering analyses. In general, a geometric model is first created and 
then the model is analyzed for loads, stresses, moment of inertia, and volume, etc. 
c) Visualization: Visualization refers to computer graphics, which includes: rendering a 
model, creation of pie charts, contour plots, shading a model, sizing, animation, etc. 
 
 
 
 
 
 
 
      Design     Analysis 
            
               
          
                                Visualization 
 
 
     
                           Components of Computer Aided Design 
 
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-1 
Chapter1 Introduction 
 
Each of these three areas has been extensively developed in the last 30 years. Several 
books are written on each of these subjects and courses are available through the 
academic institutions and the industry. 
 
Most commercial CAD packages (software) consist of only a single component: design 
or analysis or visualization. However, a few of the vendors have developed an integrated 
package that includes not only these three areas, but also includes the manufacturing 
software (CAM). Due to the large storage requirement, integrated packages use either an 
UNIX workstation or a mainframe platform, and not the popular PC platform. With the 
improvement in PC computing speed, it’s only a matter of time before we see an 
integrated package run on a PC. CAD has revolutionized the modern engineering 
practice; small and large companies use it alike, spending several billion dollars for the 
initial purchase or lease alone. CAD related jobs are high in demand and the new 
graduates have advantage over their senior colleagues, as they are more up to date and 
more productive. 
 
In this course, we will limit our coverage to the design only. Those of you interested in 
analysis area, look into the course ME 160 – Introduction to Finite Element Analysis.  
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-2 
Chapter1 Introduction 
1.2 Computer Aided Manufacturing (CAM) 
 
CAM is the next stage of CAD. A part created in CAD can be downloaded and 
manufactured, without a human hand touching the part. The process is called CAM, and 
involves CAD, Networking, and NC programming, as shown below. 
 
 
 
 
 
 
 
 
 
 
 
                               CAD   Networking 
            
               
 
                              NC programming                                     
                                                 Process planning 
                            Inspection and simulation 
     
 
    Components of Computer Aided Manufacturing 
 
 
 
 
 
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-3 
Page 4


Chapter1 Introduction 
CHAPTER 1 
 
 
 
 
INTRODUCTION 
 
 
 
 
 
 
 
 
1.1 Introduction 
 
In general, a Computer Aided Design (CAD) package has three components: a) Design, 
b) Analysis, and c) Visualization, as shown in the sketch. A brief description of these 
components follows. 
 
a) Design: Design refers to geometric modeling, i.e., 2-D and 3-D modeling, including, 
drafting, part creation, creation of drawings with various views of the part, assemblies 
of the parts, etc.  
b) Analysis: Analysis refers to finite element analysis, optimization, and other number 
crunching engineering analyses. In general, a geometric model is first created and 
then the model is analyzed for loads, stresses, moment of inertia, and volume, etc. 
c) Visualization: Visualization refers to computer graphics, which includes: rendering a 
model, creation of pie charts, contour plots, shading a model, sizing, animation, etc. 
 
 
 
 
 
 
 
      Design     Analysis 
            
               
          
                                Visualization 
 
 
     
                           Components of Computer Aided Design 
 
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-1 
Chapter1 Introduction 
 
Each of these three areas has been extensively developed in the last 30 years. Several 
books are written on each of these subjects and courses are available through the 
academic institutions and the industry. 
 
Most commercial CAD packages (software) consist of only a single component: design 
or analysis or visualization. However, a few of the vendors have developed an integrated 
package that includes not only these three areas, but also includes the manufacturing 
software (CAM). Due to the large storage requirement, integrated packages use either an 
UNIX workstation or a mainframe platform, and not the popular PC platform. With the 
improvement in PC computing speed, it’s only a matter of time before we see an 
integrated package run on a PC. CAD has revolutionized the modern engineering 
practice; small and large companies use it alike, spending several billion dollars for the 
initial purchase or lease alone. CAD related jobs are high in demand and the new 
graduates have advantage over their senior colleagues, as they are more up to date and 
more productive. 
 
In this course, we will limit our coverage to the design only. Those of you interested in 
analysis area, look into the course ME 160 – Introduction to Finite Element Analysis.  
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-2 
Chapter1 Introduction 
1.2 Computer Aided Manufacturing (CAM) 
 
CAM is the next stage of CAD. A part created in CAD can be downloaded and 
manufactured, without a human hand touching the part. The process is called CAM, and 
involves CAD, Networking, and NC programming, as shown below. 
 
 
 
 
 
 
 
 
 
 
 
                               CAD   Networking 
            
               
 
                              NC programming                                     
                                                 Process planning 
                            Inspection and simulation 
     
 
    Components of Computer Aided Manufacturing 
 
 
 
 
 
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-3 
Chapter1 Introduction 
 
1.4 Concurrent Engineering  
 
Concurrent Engineering is another powerful CAD concept that has evolved in the 90’s. 
According to this concept, there is an instantaneous communication between the 
designer, analyst, and manufacturing. Changes made at any of these work centers are 
immediately passed on to the others and the product is modified without delay. Often, the 
customer, management, and the marketing people join in and become part of the process. 
Concurrent engineering saves the valuable time and helps get the product out in the 
market quicker. Products that use to take years from the date of its concept to the actual 
production now take only a few weeks, and the final product is better and cost-effective. 
 
Some large organizations have invested in Rapid Prototyping process. In this process, the 
part is created by a CAD package and downloaded into the rapid prototyping machine; 
the machine immediately manufactures the part, using a plastic material. This is a good 
example of concurrent engineering, sometimes referred as Art to Part concept. 
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-4 
Page 5


Chapter1 Introduction 
CHAPTER 1 
 
 
 
 
INTRODUCTION 
 
 
 
 
 
 
 
 
1.1 Introduction 
 
In general, a Computer Aided Design (CAD) package has three components: a) Design, 
b) Analysis, and c) Visualization, as shown in the sketch. A brief description of these 
components follows. 
 
a) Design: Design refers to geometric modeling, i.e., 2-D and 3-D modeling, including, 
drafting, part creation, creation of drawings with various views of the part, assemblies 
of the parts, etc.  
b) Analysis: Analysis refers to finite element analysis, optimization, and other number 
crunching engineering analyses. In general, a geometric model is first created and 
then the model is analyzed for loads, stresses, moment of inertia, and volume, etc. 
c) Visualization: Visualization refers to computer graphics, which includes: rendering a 
model, creation of pie charts, contour plots, shading a model, sizing, animation, etc. 
 
 
 
 
 
 
 
      Design     Analysis 
            
               
          
                                Visualization 
 
 
     
                           Components of Computer Aided Design 
 
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-1 
Chapter1 Introduction 
 
Each of these three areas has been extensively developed in the last 30 years. Several 
books are written on each of these subjects and courses are available through the 
academic institutions and the industry. 
 
Most commercial CAD packages (software) consist of only a single component: design 
or analysis or visualization. However, a few of the vendors have developed an integrated 
package that includes not only these three areas, but also includes the manufacturing 
software (CAM). Due to the large storage requirement, integrated packages use either an 
UNIX workstation or a mainframe platform, and not the popular PC platform. With the 
improvement in PC computing speed, it’s only a matter of time before we see an 
integrated package run on a PC. CAD has revolutionized the modern engineering 
practice; small and large companies use it alike, spending several billion dollars for the 
initial purchase or lease alone. CAD related jobs are high in demand and the new 
graduates have advantage over their senior colleagues, as they are more up to date and 
more productive. 
 
In this course, we will limit our coverage to the design only. Those of you interested in 
analysis area, look into the course ME 160 – Introduction to Finite Element Analysis.  
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-2 
Chapter1 Introduction 
1.2 Computer Aided Manufacturing (CAM) 
 
CAM is the next stage of CAD. A part created in CAD can be downloaded and 
manufactured, without a human hand touching the part. The process is called CAM, and 
involves CAD, Networking, and NC programming, as shown below. 
 
 
 
 
 
 
 
 
 
 
 
                               CAD   Networking 
            
               
 
                              NC programming                                     
                                                 Process planning 
                            Inspection and simulation 
     
 
    Components of Computer Aided Manufacturing 
 
 
 
 
 
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-3 
Chapter1 Introduction 
 
1.4 Concurrent Engineering  
 
Concurrent Engineering is another powerful CAD concept that has evolved in the 90’s. 
According to this concept, there is an instantaneous communication between the 
designer, analyst, and manufacturing. Changes made at any of these work centers are 
immediately passed on to the others and the product is modified without delay. Often, the 
customer, management, and the marketing people join in and become part of the process. 
Concurrent engineering saves the valuable time and helps get the product out in the 
market quicker. Products that use to take years from the date of its concept to the actual 
production now take only a few weeks, and the final product is better and cost-effective. 
 
Some large organizations have invested in Rapid Prototyping process. In this process, the 
part is created by a CAD package and downloaded into the rapid prototyping machine; 
the machine immediately manufactures the part, using a plastic material. This is a good 
example of concurrent engineering, sometimes referred as Art to Part concept. 
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-4 
Chapter1 Introduction 
 
 
1.5 CAD/CAM History 
 
The concept of CAD and CAM is relatively new. The usage is linked with the 
development of computers. The actual application of CAD/CAM in industry, academia 
and government is only approximately 30 years old. Formal courses in CAD and Finite 
Element Analysis (FEA) were introduced in 1970’s. The major application thrust of CAD 
came in 1980’s, with the availability of PCs and workstations. In its early stage of usage, 
very few engineering companies could afford the expense of mainframe computers; 
however, PCs and workstations have evolved into affordable and adequate platform to 
support comprehensive CAD packages that initially were designed to run on the 
mainframe platform. A brief history of the evolution of CAD/CAM, according to the 
decade and the major CAD/CAM developments, is outlined below. 
 
1960’s 
• Development in Interactive computer graphics research 
• Sketchpad system developed by Ivan Sutherland in 1962 
• CAD term coined 
• First major commercial CAD/CAM software available: CADAM by Lockheed, in 1965 
• Bell Telephone’s  - Graphics 1 remote display system developed 
 
1970’s 
• Application of CAM in government, industry and academia 
• National organization formed 
• Beginning of usage of computer graphics 
• Turnkey system available for drafting 
• Wireframe and surface modeling software became available 
• Mass property calculation and FEA software became available 
• NC tape generating, verification, and integrated circuit software became available 
 
1980’s 
• CAD/CAM used for engineering research and development 
• New CAD/CAM theories and algorithms developed 
• Integration of CAD/CAM 
• Solid modeling software became available 
• Use of PCs and workstation began 
 
1990’s 
• Concept of concurrent engineering developed 
• Increased use of CAD/CAM on PCs and worksations 
• Improvements in hardware and software 
 
 
Lecture Notes © by R. B. Agarwal                     Computer Aided Design in Mechanical Engineering  1-5 
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