Vehicle Design II

Vehicle Design II (Course Overview)

Dr. Nouby M. Ghazaly Automotive and Tractor Engineering Dept.

College of Engineering, Minia University-61111

Nouby.Ghazaly@mu.edu.eg

Class Structure

Course Goals

• Provide a high quality educational experience in the field of vehicle design.

• Develop analytical and professional skills that will enable students to gain

employment in national and international companies working in the field of

mechanical design.

• Gain an advanced understanding of the types of engine components.

• Contribute to future developments in automotive technology through design of

engine components

Course Topics

1. Introduction

• Design philosophy, an overview of engine design, Applications of Computer aided

Design (CAD) and Finite Element Analysis (FEA) in Engine Design.

• History of automobile engines, Classification of engines, Principle of engine

operation (SI & CI). Engine support mountings. (8hrs) (2Q)

2. Dynamic of a slider-crank mechanism . (4hrs) (1Q)

3. Design of Cylinders Block and Cylinder liners, details of water jacket, dry and wet

liners, Design of Cylinder head, Cylinder arrangement. (4hrs) (1Q).

4. Design of Piston Assembly, piston rings, piston pin - stress analysis, methods of

manufacture, heat treatment, piston ring selection, limits of fit for pins. (4hrs) (1Q).

5. Design of Connecting rod assembly (small end- Big end- Shank) (4hrs) (1Q).

6. Design of Crank shaft, firing order, balancing and torsional vibration analysis,

vibration dampers. (4hrs) (1Q).

7. Design of Flywheel; Camshaft - drives of cams, materials, Types. (4hrs) (1Q).

REFERENCE BOOKS

1. Shigley J.E. “Mechanical Engineering Design” McGraw Hill, 2003.

2. Garrett T.K., Newton K. and Steeds W. “The Motor Vehicle” Reed Educational and Professional Publishing, 2001.

3. Kolchin A., Demidov V. “Design of Automotive Engines” Mir Publishers, 1984.

4. Willard W. Pulkrabek “Engineering Fundamentals of the Internal Combustion Engine” Prentice Hall, 1997.

5. Richard D. Atkins “An Introduction to Engine Testing and Development” SAE International, USA, 2009.

Lecture (1)

• Design philosophy

• an overview of engine design

• Applications of Computer aided Design (CAD)

• Finite Element Analysis (FEA) in Engine Design.

Design Philosophy

• What is Engineering?

• Engineering is not usually considered a science. Science is about discovering the natural. Engineering is creating the artificial.

• Engineers apply the principles of science and mathematics to develop solutions to problems.

• The main philosophy behind all of the engineering and engineering design activities is to serve the people, society and mankind.

• This is why the engineering design is defined as an activity to satisfy a need. A need is real only if it is defined and identified by a human.

What is Design?

• Design is a interaction between what we want to achieve and how we want to satisfy them.

• Design is a process of converting information that characterize the needs and requirements for a product into knowledge about the product.

• Engineering design is densely creative at the beginning, and significance of creativity decreases towards the end of the process,

• Engineering design is iterative during the whole design process both at macro scale and at element scale,

Scientific Principles and Technology

Design Information

Product

Work

Feedback

Design Process

Evaluation

DESIGN OF AN ENGINE

• Consider for an example, design of an engine. A number of factors need be considered:

• (a) The purpose for which the engine is to be designed such as whether it is to be used as external combustion engine or internal combustion engine.

• (b) If we selected internal combustion engine, whether the engine is to be designed for a heavy truck, bus, ship or a passenger car.

• (c) Material for the engine, its strength and cost need to be determined.

• (d) Finally, the art and methodology of the designed engine.

BASIC STEPS IN MECHANICAL

DESIGN PROCESS

1) Problem Definition

Constraints , Who’s the Customer?

Data gathering: What is known, what is not.

2) Literature Search: What are possible solutions?

3) Analysis , Modeling

4) Develop ideas for a solution

Solution Evaluation, Failure Mode Effect Analysis

Optimization, Design for Manufacturability

5) Prototype Fabrication

6) Testing, Modification

7) Volume Production

8) Continuous verification and Testing, Customer Feedback

9) Take data to verify your gains or improvements

Types of Design

• There are different types of design:

• New Design: New tasks and problems are solved by new solution principles.

• Revised Design: The embodiment design is customized/adapted to fit new requirements. The employed solution principles are known and field-proven.

• Variant Design: Size and/or structure of parts and assemblies are varied within the limits of the already planned system.

• Repeat Design: A new start of the production run with an unchanged design.

• Robust design: A systematic engineering based methodology (which is part of quality engineering process) that develops and manufactures high reliability products at low cost with reduced delivery cycle.

Factors to be considered

in machine design • There are many factors to be considered while attacking a design problem. In

many cases these are a common sense approach to solving a problem. Some of these factors are as follows:

• (a) What device or mechanism to be used? This would decide the relative arrangement of the constituent elements.

• (b) Material

• (c) Forces on the elements

• (d) Size, shape and space requirements. The final weight of the product is also a major concern.

• (e) The method of manufacturing the components and their assembly.

• (f) How will it operate?

• (g) Reliability and safety aspects

• (h) Maintenance, cost and aesthetics of the designed product.

CAD/CAM/CAE

• Computer-Aided Design (CAD) is the technology

• concerned with the use of computer systems to assist in

• the creation, modification, analysis, and optimization of a

• Design.

• Computer-Aided Manufacturing (CAM) is the technology

• concerned with the use of computer systems to plan,

• manage, and control manufacturing operations.

• Computer-Aided Engineering (CAE) is the technology

• concerned with the use of computer systems to analyze

• CAD geometry, allowing the designer to simulate and study how the product will behave.

Computer-Aided Design (CAD)

• Use of computer systems to assist in the creation, modification, analysis, and optimization of a design

• Typical tools:

– Tolerance analysis

– Mass property calculations

– Finite-element modeling and visualization

• Defines the geometry of the design

Computer-Aided Design (CAD)

• Use of computer systems to assist in the creation, modification, analysis, and optimization of a design

• Typical tools:

– Tolerance analysis

– Mass property calculations

– Finite-element modeling and visualization

• Defines the geometry of the design

Computer-Aided Design (CAD)

• Use of computer systems to assist in the creation, modification, analysis, and optimization of a design

• Typical tools:

– Tolerance analysis

– Mass property calculations

– Finite-element modeling and visualization

• Defines the geometry of the design

Computer-Aided Engineering

(CAE)

• Use of computer systems to analyze CAD geometry

• Allows designer to simulate and study how the product will behave, allowing for optimization

• Finite-element method (FEM) – Divides model into

interconnected elements – Solves continuous field

problems

CAE applications

• CAE applications support a wide range of engineering disciplines or phenomena including:

1. Stress and dynamics analysis on components and assemblies using finite element analysis (FEA)

2. Thermal and fluid analysis using computational fluid dynamics (CFD)

3. Kinematics and dynamic analysis of mechanisms (multibody dynamics)

4. Mechanical event simulation (MES)

5. Control systems analysis

6. Simulation of manufacturing processes like casting, molding and die press forming

7. Optimization of the product or process

Benefits of CAE

• The benefits of CAE include reduced product development cost and time, with improved product quality and durability.

1. Design decisions can be made based on their impact on performance.

2. Designs can be evaluated and refined using computer simulations rather than physical prototype testing, saving money and time.

3. CAE can provide performance insights earlier in the development process, when design changes are less expensive to make.

4. CAE helps engineering teams manage risk and understand the performance implications of their designs.

5. Integrated CAE data and process management extends the ability to effectively leverage performance insights and improve designs to a broader community.

6. Warranty exposure is reduced by identifying and eliminating potential problems. When properly integrated into product and manufacturing development, CAE can enable earlier problem resolution, which can dramatically reduce the costs associated with the product lifecycle.

Computer-Aided Manufacturing

(CAM)

• Use of computer systems to plan, manage, and control manufacturing operations

• Direct or indirect computer interface with the plant’s production resources

• Numerical control of machine tools

• Programming of robots

Integrated

CAD/CAE/CAM Systems • Professional CAD/CAE/CAM Tools

• – CATIA (Dassault Systemes - IBM)

• – Unigraphics NX (Electronic Data Systems Corp - EDS)

• – I-DEAS (EDS)

• – Pro/ENGINEER (PTC)

• • Other CAD and Graphics Packages

• – AutoCAD Mechanical Desktop

• – SolidWorks (CATIA)

• – Solid Edge (EDS)

• – MicroStation

• – Intergraph

Pro/ENGINEER

• One of the CAD/CAM/CAE industry’s leading suppliers of

software tools from Parametric Technology Corp. (PTC)

• A pioneer of the new feature-based, parametrically driven

design paradigm in late 1980s, now industrial standard.

• A system used to automate the development of a mechanical

product from its conceptual design through production.

• Offering integrated software technologies to reduce time to

market, improve engineering process, and optimize product

quality.

• One of the fastest growing companies in the mechanical

design automation market

• Improved user’s interface in recent release.

Unigraphics- NX

• A full spectrum design modeling, analysis, simulation,

and manufacturing CAD/CAE/CAM software from

Unigraphics Solutions

• One of the older and well-established CAD/CAE

system.

• A software of choice for a wide variety of applications,

especially in automotive and aerospace product

development.

CATIA

• A process-centric CAD/CAM software solution marketed

exclusively by IBM and developed by Dassault Systems

• A system used to design and manufacture many complex

3D products. Today, 7 out of every 10 airplanes and 4 out

of every 10 cars are designed using CATIA-CADAM

Solutions, making it the de facto standard for these

markets.

• A software of choice for a wide variety of applications

ranging from consumer goods and machinery to plant

design and shipbuilding.

• 300,000 CATIA users worldwide, nearly half in English

language markets

Finite Element Analysis in Design

• The continuum has an infinite number of degrees-of-freedom (DOF), while the

discretized model has a finite number of DOF. This is the origin of the name, finite

element method.

• The number of equations is usually rather large for most real-world applications of

the FEM, and requires the computational power of the digital computer. The FEM

has little practical value if the digital computer were not available.

• Advances in and ready availability of computers and software has brought the FEM

within reach of engineers working in small industries, and even students

• Most commercial FEM software packages originated in the 1970s (ABAQUS,

ADINA, ANSYS, MARK, PAFEC) and 1980s (FENRIS, LARSTRAN ‘80, SESAM

‘80.)

Finite Element Analysis in

Design FEA programs simulate static, dynamic, linear, nonlinear, thermal, modal, and random vibrations, and more. FEA solves many different problems out of which structural and thermal problems are most common for mechanical engineers.

• "Structural analysis finds deformations, strains, and stresses caused by structural loads such as force, pressure, and gravity.

• Thermal analysis finds temperatures, temperature gradients, and heat flow caused by thermal loads such as heat flux or heat power. Boundary conditions such as prescribed temperatures and convection coefficients also affect results.

Finite element model of

the gasoline SI engine

Applications in FEA

Lecture (2)

Is it possible to build Egyptian car

?

Questions?