Chapter 1

1. Chapter 1 An Introduction to Graphical Communication in Engineering

2. Objectives • Explain and illustrate how engineering graphics is one of the special tools available to an engineer • Define how engineering visualization, modeling, and graphics are used by engineers in their work

3. Objectives (cont’d.) • Provide a short history of how engineering graphics, as a perspective on how it is used today, was used in the past

4. Introduction • Roles of engineering graphics: • Communication • Record keeping • Analysis • Computers, three-dimensional modeling, and graphics software: • Made it increasingly effective to use engineering graphics in design, visualization, and optimization

5. A Short History • Ancient history • Cave paintings • Egyptian pyramids, Native American pyramids • Egyptian hieroglyphics • Roman arch, Roman road • Archimedes screw • Diagrams depicting its use

9. The Medieval Period • Europe: large building construction • Flying buttress • Towers • Asia: large fortifications, shrines, and temples • Great Wall of China • Large-scale civil engineering projects

10. The Renaissance • Physical scientific thinking • Empirical observations and mathematics • Accurate sizing • Descriptive geometry • Fortifications • By 1800s, most engineering was civil or military

11. Descriptive Geometry

12. The Industrial Revolution Began with mechanical engineering Mass production Each product identical Short production times Engineering schools Communication necessary Patent drawings vs. engineering drawings

15. More Recent History • Electrical engineering • Electric motors, generators, power conversion, and transmission lines • Chemical engineering • Production of petroleum products and synthetic chemicals • Industrial and manufacturing engineering • Improving production quality, control, and efficiency

16. More Recent History (cont’d.) • Nuclear engineering • Result of the nuclear energy and nuclear weapons programs • More recent disciplines • Bioengineering, information and computational sciences, micro-electro-mechanical systems (MEMS), and nano-engineering

18. The People and Their Skills • Many people with many different types of skills participate in development and production of a project • Clear, unbroken, and unambiguous flow of communication must take place • Graphical communication must follow universally accepted standards

20. Organization of Project Life Phases • Concept • Design • Fabrication • Installation • Operation • Disposal

21. Organization of Functional Groups • Research and Development • Design • Manufacturing • Sales and/or Buying • Service • Subcontractors

22. Organization of Skills • Engineers • Ensure systems operate within limits • Specify materials and sizes of parts and assemblies • Designers • Responsible for product’s fit and finish • Drafters • Responsible for documentation

23. Organization of Skills (cont’d.) • Fabricators • Make the parts • Inspectors • Responsible for checking • Technicians • Responsible for maintenance and operation

24. Concurrent Engineering • Process where design and aspects of fabrication phases are combined • Different groups of engineers work together • Product design may be altered to facilitate fabrication • Advantage: product development reduced • Disadvantage: large errors in design are expensive

25. Engineering Graphics Technology • Early years • Up until Renaissance period, most drawings done by hand • Many drawings were distorted and done in 2-D • Good for conveying ideas and rough sizing • Poor for precision • Made part interchangeability and mass production difficult

26. Instrument Drawing • Early instruments: straightedges with scales, compasses, dividers, protractors • Other classic drawing instruments include: • Drafting board • T square • Triangle • French curve • Template

27. The Computer Revolution • Advantages of computer-based graphics • Ease of data storage and transmission • Precise drawing data • Ease of data manipulation • Computer-aided drawing (CAD) software • Developed in 1970s for mainframes • Became popular in 1980s because of PCs

30. Graphics as a Design Tool • Three-dimensional (3-D) modeling • Began in 1980s as an engineering design tool • Quickly adopted by mechanical engineering; called solid modeling • Permitted viewing a 3-D object from different perspectives, unlike CAD • Aided in visualization • Required more computation power and memory than CAD

31. Graphics as an Analysis Tool • Descriptive geometry still useful in large-scale civil, architectural, and mining projects • Solid modeling used to calculate mechanical properties of parts • 3-D land models • Make visualization of landscapes easier

32. Graphics as a Presentation Tool • Charts • Commonly used for presenting data to general public • Graphs • More technical; show data trends • Geometric models built with three-dimensional modeling software • Finite element analysis (FEA)

33. The Modern Role of Engineering Graphics • Best way to communicate idea for part is to show a picture • Now computer-generated from 3-D models • Engineering graphics is still analysis tool, but type of analysis has changed • Now, graphical models examine fit and function

35. The Modern Role of Engineering Graphics (cont’d.) • Modern graphics classes mainly cover: • Visualization • Analysis • Function • Optimization of designs • Sketching

36. Summary • Learned that graphical communication is vital in nearly all aspects of engineering • Learned that technological tools have made tasks associated with classical engineering graphics much easier • Discussed 3-D modeling and its impact on engineering graphics