1. 6. Computer Aided Design and Production Process
ME 521
Computer Aided Design
6. Computer Aided Design and Production Process
Assoc.Prof.Dr. Ahmet Zafer Şenalp
Mechanical Engineering Department
Gebze Technical University

2. Design and Production Process
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

3. Mechanical Engineering Department, GTU
Product design
6. Computer Aided Design
and Production Process
Product design is the process of creating a new product to be sold by a business to its customers.
A very broad concept, it is essentially the efficient and effective generation and development of ideas through a process that leads to new products.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

4. Design and Production Process
6. Computer Aided Design
and Production Process
The product begins with a need which is identified based on customers' and markets' demands.
The product goes through two main processes from the idea conceptualization to the finished product:
The design process
The manufacturing process
The main sub-processes that constitute the design process are:
Synthesis
Analysis
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

5. Mechanical Engineering Department, GTU
Synthesis
6. Computer Aided Design
and Production Process
• Ideate: The designers here brainstorm different ideas, solutions for their design problem. The ideal brainstorming session does not involve any bias or judgment, but instead builds on original ideas.
• Select: By now, the designers have narrowed down their ideas to a select few, which can be guaranteed successes and from there they can outline their plan to make the product.
• Implement: This is where the prototypes are built, the plan outlined in the previous step is realized and the product starts to become an actual object.
• Evaluate: In the last stage, the product is tested, and from there, improvements are made. Although this is the last stage, it does not mean that the process is over. The finished prototype may not work as well as hoped so new ideas need to be brainstormed.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

6. Mechanical Engineering Department, GTU
Analysis
6. Computer Aided Design
and Production Process
Accept Situation: Here, the designers decide on committing to the project and finding a solution to the problem. They pool their resources into figuring out how to solve the task most efficiently.
Analyze: In this stage, everyone in the team begins research. They gather general and specific materials which will help to figure out how their problem might be solved. This can range from statistics, questionnaires, and articles, among many other sources.
First of all analyses model should be constructed based on the conceptual design. The number of analyses can be more than one.
With combining conceptual design and analyses model a design is obtained.
Design analyses and optimization is applied on the design.
Finally the design is evaluated.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

7. Design and Production Process
6. Computer Aided Design
and Production Process
Implementation of a Typical CAD Process on a CAD/CAM system
Delineation of geometric model
Definition translator
Geometric model
Design and
Analysis algorithms
Drafting and
detailing
Documentation
To CAM Process
Interface algorithms
Design changes
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

8. CAD Tools Required to Support the Design Process
6. Computer Aided Design
and Production Process
Design phase
Required CAD tools
Design conceptualization
Geometric modeling techniques; Graphics aids; manipulations; and visualization
Design modeling and simulation
Same as above; animation; assemblies; special modeling packages
Design analysis
Analysis packages; customized programs and packages
Design optimization
Customized applications; structural optimization
Design evaluation
Dimensioning; tolerances; BOM; NC
Design communication and documentation
Drafting and detailing
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

9. CAM Tools Required to Support the Design Process
6. Computer Aided Design
and Production Process
Manufacturing phase
Required CAM tools
Process planning
CAPP techniques; cost analysis; material and tooling specification
Part programming
NC programming
Inspection
CAQ; and Inspection software
Assembly
Robotics simulation and programming
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

10. Automation and CAD/CAM
6. Computer Aided Design
and Production Process
Automation can be defined as the technology concerned with the application of complex mechanical, electronic, and computer-based systems in the operation and control of manufacturing systems
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

11. Process structures for manufacturing
6. Computer Aided Design
and Production Process
Five key process types:
- Project Process
- Job process
- Batch process
- Line process
- Continuous flow process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

12. Mechanical Engineering Department, GTU
Project Processes
6. Computer Aided Design
and Production Process
One-off, complex, large scale, high work content “products”
Specially made, every one customized
Defined start and finish: time, quality and cost objectives
Many different skills have to be coordinated
Fixed position layout
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

13. Mechanical Engineering Department, GTU
Project Processes
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

14. Mechanical Engineering Department, GTU
Job processes
6. Computer Aided Design
and Production Process
Very small quantities: “one-offs”, or only a few required
Specially made. High variety, low repetition.
Skill requirements are usually very broad
Skilled jobber, or team of jobbers complete whole product
Fixed position or process layout (routing decided by jobbers)
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

15. Mechanical Engineering Department, GTU
Job processes
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

16. Mechanical Engineering Department, GTU
Batch Processes
6. Computer Aided Design
and Production Process
Higher volumes and lower variety than for jobbing
Standard products, repeating demand. But can make specials
Specialized, narrower skills
Set-ups (changeovers) at each stage of production
Process or cellular layout
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

17. Mechanical Engineering Department, GTU
Batch Processes
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

18. Mechanical Engineering Department, GTU
Mass (Line) Processes
6. Computer Aided Design
and Production Process
Higher volumes than Batch
Standard, repeat products
Low and/or narrow skills
No set-ups, or almost instantaneous ones
Cell or product layout
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

19. Mechanical Engineering Department, GTU
Mass (Line) Processes
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

20. Mechanical Engineering Department, GTU
Continuous Process
6. Computer Aided Design
and Production Process
Extremely high volumes and low variety: often single product
Standard, repeat products
Highly capital-intensive and automated
Few changeovers required
Difficult and expensive to start and stop the process
Product layout: usually flow along conveyors or pipes
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

21. Mechanical Engineering Department, GTU
Continuous Process
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

22. Process structures for manufacturing
6. Computer Aided Design
and Production Process
Volume
Low
High
Variety
Project
Jobbing
Batch
Mass
Contin-
uous
Professional service
Service shop
Mass service
Service process types
Manufacturing process types
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

23. Mechanical Engineering Department, GTU
CIM
6. Computer Aided Design
and Production Process
COMPUTER INTEGRATED MANUFACTURING (CIM)
Computer-integrated manufacturing (CIM) is the manufacturing approach of using computers to control the entire production process.
This integration allows individual processes to exchange info with each other and initiate actions.
Through the computers integration, manufacturing can be faster and less error-prone, although the main advantage is the ability to create automated manufacturing processes.
Typically CIM relies on closed-loop control processes, based on real-time input from sensors.
It is also known as flexible design and manufacturing
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

24. Mechanical Engineering Department, GTU
CIM
6. Computer Aided Design
and Production Process
Three Distinguished Components (CIM)
As a method of manufacturing, three components distinguish CIM from other manufacturing methodologies:
Means for data storage, retrieval, manipulation and presentation
Mechanisms for sensing state and modifying processes
Algorithms for uniting the data processing component with the sensor/modification component
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

25. Mechanical Engineering Department, GTU
Benefits of CIM
6. Computer Aided Design
and Production Process
Integration of technologies brings following benefits:
1. Creation of a truly interactive system that enables manufacturing functions to communicate easily with other relevant functional units.
2. Accurate data transferability among manufacturing plant or subcontracting facilities at implant or diverse locations.
3. Faster responses to data-changes for manufacturing flexibility.
4. Increased flexibility towards introduction of new products.
5 Improved accuracy and quality in the manufacturing process.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

26. Mechanical Engineering Department, GTU
HARDWARE IN CIM
6. Computer Aided Design
and Production Process
Devices and equipment required:
CNC, Computer numerical controlled machine tools
DNC, Direct numerical control machine tools
PLCs, Programmable logic controllers
Robotics
Computers
Software
Controllers
Networks
Interfacing
Monitoring equipment
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

27. Computer Aided Process Planning (CAPP)
6. Computer Aided Design
and Production Process
CAPP is the use of computer technology to aid in the process planning of a part or product in manufacturing.
CAPP is the link between CAD and CAM in that it provides for the planning of the process to be used in producing a designed part
Process planning is a production organization activity that transforms a product design into a set of instruction (sequence, machine tool setup etc.) to manufacture machined part economically and competitively
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

28. Computer Aided Process Planning (CAPP)
6. Computer Aided Design
and Production Process
CAPP
Computer Aided Design
(CAD)
Computer Aided Manufacturing
(CAM)
Synergy results in when CAM is integrated with CAD to form CAD/CAM systems than a stand alone CAD or CAM systems. In such a system CAPP becomes a direct connection between design and manufacturing
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

29. Computer Aided Process Planning (CAPP)
6. Computer Aided Design
and Production Process
Benefits derived from CAPP
• Process rationalization and standardization
• Increased productivity of process planners
• Reduced lead time for process planning
• Improved legibility
• Incorporation of other application programs
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

30. Computer Aided Process Planning (CAPP)
6. Computer Aided Design
and Production Process
COMPUTER AIDED PROCESS PLANNING (CAPP) ROLES IN MANUFACTURING
Used to develop a product manufacturing plan based on projected variables such as cost, lead times, equipment availability, production volumes, potential material substitution routings and testing requirements.
CAPP is a decision-making process, it determines a set of instruction and machining parameters required to manufacture a part.
Integrates and optimizes system performance for every product/component to ensure functionality aspect and design specifications meet requirements.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

31. Computer Aided Process Planning (CAPP)
6. Computer Aided Design
and Production Process
CAPP System Architecture
CAD System
Preprocessor
Machining
Knowledge base
Machining selection
module
Constraint
Creation module
Constraint application
module
Process plan
generation module
Manufacturing
knowledge base
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

32. Computer Aided Process Planning (CAPP)
6. Computer Aided Design
and Production Process
Two method in Process Planning:
The manual experience based planning method
The manual experience based process planning is most widely used
It is mainly based on a manufacturing engineer's experience
and knowledge of production facilities, equipment, their
capabilities, processes and tooling. .
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

33. Computer Aided Process Planning (CAPP)
6. Computer Aided Design
and Production Process
b) Computer Aided Process Planning
Purpose of process planning is to translate the design requirements into manufacturing
process details
A system was developed in which design information is processed by the process planning system to generate manufacturing process details.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

34. Computer Aided Process Planning (CAPP)
6. Computer Aided Design
and Production Process
CAPP Programming software
LISP
Is a functional programming language and offer flexibility in writing rules so that can use logical programming language .
PROLOG
Programming in PROLOG involves writing logical formula which indicate logic relation in problem.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

35. Computer Aided Process Planning (CAPP)
6. Computer Aided Design
and Production Process
Contribution CAPP in implementation of CIM
The improved quality can be achieved through
better design and better quality control in the
manufacturing control.
Improved production scheduling, improved cost
estimating procedures and fewer calculation errors.
The system will be more efficient and organized in
engineering, production, marketing, and support
functions of a manufacturing.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

36. Integrating The Design and Manufacturing Process Through a Common Datase -A Scenario
6. Computer Aided Design
and Production Process
Example: Audio system cabinet design
Goals:
Better quality
Lower cost
Quick delivery
Design description: 4 spaces are needed in the cabinet
CD player
2. Cassette player
3. Reciever
4. Storage compartment of CD’s
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

37. Mechanical Engineering Department, GTU
Integrating The Design and Manufacturing Process Through a Common Datase -A Scenario
6. Computer Aided Design
and Production Process
Preliminary Design:
The designer can draw a lot of design concepts.
During this phase, according to the need can make 2 or 3 dimensional models
Photorealistic images of preliminary designs can be created.
Preliminary designs submitted to acceptance:
The design concept is sent to the market via to measure the response
Selection of the model that should be designed and feasibility study:
Most admired model that collects the most sales potential will be the selected model.
When the design concept is completed, data is stored to the database:
furniture fiction: The amount of shelf, the information such where to use which shelf are categorised and saved to database and in need can be recalled from the database and changed accordingly.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

38. Mechanical Engineering Department, GTU
Integrating The Design and Manufacturing Process Through a Common Datase -A Scenario
6. Computer Aided Design
and Production Process
Determining the dimensions of the cabinet:
Its overall size should be determined so that each space within it can accommodate various models of the audio components on the market. Thus it is necessary to obtain information on the sizes of the audio components available. This information may be obtained from catalogs or retrieved from manufacturers' or distributors' databases.
Determining the material to be used for the cabinet:
The designer could specify natural oak, natural pine, particle board, steel sheet, or some other material.
However, in the case of products that operate under severe conditions, such as mechanical assemblies, the designer must be guided by the material's properties. The database is useful in this phase also because properties of many materials can be stored in it for later retrieval and use.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

39. Mechanical Engineering Department, GTU
Integrating The Design and Manufacturing Process Through a Common Datase -A Scenario
6. Computer Aided Design
and Production Process
Determining the thickness of each shelf and door and the side walls:
The thickness of the shelves must be sufficient to avoid deflection caused by the weight of the audio components. However, in mechanical assemblies requiring high accuracy or a structure supporting heavy loads, dimensions such as thickness must be determined to avoid excessive deformation. The finite-element method is generally used to calculate the deformation of a structure.
By evaluating the deflection of the shelves while varying the thickness of the shelves, the designer can determine the proper thickness of the shelves and store that information in the database.
In addition acoustic analysis may be necessary.
Assembly   technique:
Assembly   technique is determined by an expert system.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

40. Mechanical Engineering Department, GTU
Integrating The Design and Manufacturing Process Through a Common Datase -A Scenario
6. Computer Aided Design
and Production Process
Cabinet details:
When the design conceptualization, analysis, and optimization phases have been completed, the designer moves on to design documentation to specify the details of the cabinet.
The part drawings of the shelves, doors, and side walls are generated by using computer-aided drafting. In this phase, the designer can add more details for aesthetic purposes.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

41. Mechanical Engineering Department, GTU
Integrating The Design and Manufacturing Process Through a Common Datase -A Scenario
6. Computer Aided Design
and Production Process
To make the cabinet, each part shape is arranged on the raw material, in this case sheets of wood, and cut out with a saw.
Waste can be reduced by arranging the parts efficiently on the wood sheets. The designer can try various parts layouts on the com­puter screen until obtaining a layout with minimum waste. The computer program can facilitate this process by calculating the amount of waste for each layout. Also a nesting program that automatically provides the most economic layout can be used.
Furthermore, software tools may be used to design the jigs and fixtures for this cutting process and to pro­gram the materials handling systems. These systems may be conveyor belts or robots that transfer the raw material and the cut parts to and from the saw.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

42. Mechanical Engineering Department, GTU
Integrating The Design and Manufacturing Process Through a Common Datase -A Scenario
6. Computer Aided Design
and Production Process
Once prepared, the parts have to be assembled. Ideally, the assembly process can also be carried out by robots that are programmed automatically from the descriptions of the final product and its parts that are stored in the database.
The jigs and fixtures for the assembly process can also be designed simultaneously.
In addition, a robot can be programmed to paint the cabinet after it has been assembled.
This scenario is summarized in figure given in next page. It shows how the CAD, CAM, and CAE activities are integrated through the database, which is the objective of CIM.
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

43. CAD, CAM and CAE Integration Through the Database
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

44. Mechanical Engineering Department, GTU
Part Model
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

45. Mechanical Engineering Department, GTU
Finite Element Mesh
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

46. Applying Boundary Conditions
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

47. Results:Displacement
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

48. Results:Equivalent Stress
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

49. Pressure Vessel Analysis
6. Computer Aided Design
and Production Process
Geometric model
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

50. Pressure Vessel Analysis
6. Computer Aided Design
and Production Process
Finite element model
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

51. Pressure Vessel Analysis
6. Computer Aided Design
and Production Process
Boundary conditions
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

52. Pressure Vessel Analysis
6. Computer Aided Design
and Production Process
Equivalent stress distributions
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

53. Example Part Solid Model
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

54. Finite Element Analysis
6. Computer Aided Design
and Production Process
Finite Element Analysis
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

55. Mechanical Engineering Department, GTU
Flow Analysis
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

56. Mechanical Engineering Department, GTU
Die Design
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU

57. Mechanical Engineering Department, GTU
CNC Cutter Locations
6. Computer Aided Design
and Production Process
Dr. Ahmet Zafer Şenalp ME 521
Mechanical Engineering Department, GTU