Using Industrial Hydraulics |
Applications of Computer-Aided Manufacturing
Contents of this Guide:
PART 1 -- Minds-On
Summary of this Guide:
Engineers have made remarkable innovations during the twentieth century. The National Academy of Engineering (NAE) recently identified the top 20 engineering achievements of the twentieth century that "shaped a century and changed the world."
NATIONAL ACADEMY OF ENGINEERING -- TOP 20 ENGINEERING ACHIEVEMENTS OF THE 20TH CENTURY
However, engineering freshmen are less interested in what was or what is than they are in what will be.
Young men and women exploring engineering as a career are excited about the future-their future-and about the engineering challenges 10 to 20 years from now when they are in the spring and summer of their careers. In the words of the four-time Stanley Cup winner and Hockey Hall of Fame member Wayne Gretzky, I skate to where the puck is going to be, not where it's been.
The National Academy of Engineering also has proposed the following 14 Grand Challenges for Engineering in the 21 st Century. In our second edition of this text, we have chosen to highlight material that engages these topics because they represent the future of engineering creativity.
NATIONAL ACADEMY OF ENGINEERING -- ENGINEERING CHALLENGES FOR THE 21ST CENTURY
The twenty-first century will be filled with many exciting challenges for engineers, architects, physicians, sociologists, and politicians. Figure 1 illustrates an enhanced set of future challenges as envisioned by Joseph Bordogna, Deputy Director and Chief Operating Officer of the National Science Foundation.1
Cognitive Revolution Diverse Workforce Creative Transformation Information Explosion Demographic Shifts Environmental Sustainability Finite Resources International Partnerships Global Economy Infrastructure Renewal Continuous Innovation Career-Long Learning
Future Trajectories in Science, Engineering, and Technology
The Structure of this Guide
In this guide we have tried to provide an exciting introduction to the engineering profession. Between its covers you will find material on classical engineering fields as well as introductory material leading to emerging twenty-first century engineering fields such as bioengineering, nanotechnology, and mechatronics.
This guide is divided into two parts; most sections in Part 1 are organized around just one or two principles and have several worked examples and include exercises with an increasing level of complexity at the end of the section. Answers are given to selected exercises to encourage students to work toward self-proficiency.
Part 1 covers introductory material explicitly from the following engineering sub-disciplines: bioengineering, chemical engineering, civil engineering, computer and electronic engineering, control systems engineering, electrical engineering, electrochemical engineering, materials engineering, manufacturing engineering and mechanical engineering and an introduction to engineering economics. The second edition of this text is organized around the theme of 21st century engineering and provides a forward-looking entry into each of the engineering sub-disciplines listed.
The topics covered are kept to a level compatible with the background of first year students. Some topics obviously are closer to the core material in one subdiscipline of engineering than to another, and some are generic to all. In order to cover such broad, and sometimes relatively advanced, subject matter we have taken some liberties in simplifying those topics. Instructors may expect to find shortcuts that will pain the purists; we have tried, nevertheless, to be accurate as to basic principles.
Part 2 provides the content for a Design Studio, and is associated with the design of engineering systems.
This "Hands-on" section is just as essential and challenging as the minds-on aspects covered in Part 1. Also, for most students, it is a lot more fun. Few things are more satisfying than seeing a machine, an electronic device, or a computer program you have designed and built doing exactly what you intended it to do. Such initial successes may sound simple, but they provide the basis of a rigorous system that will enable an engineering graduate, as part of a team of engineers, to achieve the even greater satisfaction in designing a system that can provide new means of transportation, information access, medical care, energy supply, and such, and can change for the better the lives of people around the world.
We physically separated the two parts of this text to emphasize the different character of their content.
Each section of the minds-on section has about the equivalent amount of new ideas and principles; our experience is that any section can be sufficiently covered in about two hours of lecture class time, and that the students can complete the rest of the section unaided. On the other hand, the Design Studio needs up to three contiguous laboratory hours per week to do it justice. It culminates in a team-orientated competition. Typically, student teams build a small model "device" that has wheels, or walks, or floats, that may be wireless or autonomous, and so forth. Students then compete head-to-head against other teams from the course with the same design goals plus an offensive and defensive strategy to overcome all the other teams in the competition. Our experience is that this is highly motivating for the students.
There is too much material, as well as too broad coverage, in this text provided for just one introductory course. Given the necessary breaks for testing and for a final examination, typically a class will cover several sections of Part 1. Exactly which sections will depend on the engineering disciplines offered at your institution. We certainly think the more fundamental sections need to be included. Suggested Part I coverage should include the basics in Sections 2, 3 and 4 plus several other sections that can be selected for suitability for particular students' sub-disciplines. Part 2 of this text can be thought of as independent of Part 1, but should be taught as an integral part of a first-year engineering course.
The approach taken in this first year text is unique, in part because of the atypical character of authorship.
Two of the authors have industrial backgrounds, with one in engineering research and applied science and the other in industrial communications and bring a working knowledge of what is core to a practicing engineer. The other two authors have followed more traditional academic career paths and have the appropriate academic experience and credentials upon which to draw. We believe the synergy of the combined authorship provides a fresh perspective for first-year engineering education. Specifically, though elementary in coverage, this guide parallels the combined authors' wide experience that engineering is not a "spectator sport" We therefore do not duck the introduction of relatively advanced topics in this otherwise elementary guide. Here are some of the nonstandard approaches to familiar engineering topics.
We introduce spreadsheets early in the guide, and almost every section of Part 1 has one or more spreadsheet exercises.
We try to rigorously enforce the use of appropriate significant figures throughout the text. For example, we always try to differentiate between 60. and 60 (notice the decimal point or its absence). We obviously recognize often it appears to be clumsy to write numbers such as 6.00 _ 101 but we do so to discourage bad habits such as electronic calculator answers to undeserved significant figures.
We develop all 2 our exercise solutions in a rigorous format using a simple mnemonic Need-Know- How-Solve to discourage the student who thinks he or she knows the answer and writes the wrong one down (or even the correct one!). This too can appear to be clumsy in usage, but it is invaluable in training a young engineer to leave an audit trail of his or her methods, a good basic work habit of practicing engineers.
We recognize that the Engineering English unit system of lbf, lbm, and gc will be used throughout the careers of many, if not most, of today's young engineers. A clear exposition is used to develop it and to use it so we can avoid the terrible results of a factor of 32.2 that should or shouldn't be there! Conservation principles, particularly energy and mass, are introduced early in the text as well as emphasis on the use of control boundaries that focus on the essential problem at hand.
The use of tables is a powerful tool, both in the hands of students and of qualified engineers. We have developed a number of tabular methods for stoichiometric and for thermodynamic problems that should eliminate the problem of the wrong stoichiometric coefficients and of sign errors, respectively.
Methods based on tables are also fundamental to design principles as taught in the Design Studio section of the guide.
We have emphasized the power of electrical switches as vital elements of computer design and their mathematical logic analogues.
Since standard mathematical control theory is far too advanced for our intended audience, we have used spreadsheet methods that graphically show the effects of feedback gains, paralleling the results of the standard mathematical methods. Most students will still find this section to be very challenging.
We have developed a simple solution method for standard one-dimensional kinematics problems using a visual/geometric technique of speed-time graphs rather than applying the standard equations by rote.
We believe this is a usefully visual way to deal with multi-element kinematics problems. Of course we have also quoted, but not developed, the standard kinematics equations because they are derived in every introductory college textbook and their use does not increase basic understanding of kinematics per se.
The design methodology in the Design Studio is presented in a stepwise manner to help lead student and instructor through a hands-on design project.
Pacing of hands-on projects is accomplished through design milestones. These are general time-tested project assignments that we believe are the most powerful tool in getting a freshman design course to work well.
The many design examples were selected from past student projects, ranging from the freshman to the senior year, to appeal to and be readily grasped by the beginning engineering student. In one section we present a couple of typical first-year design projects and follow the evolution of one team's design from clarification of the task to detailed design.
The culmination of the hands-on Design Studio is a head-to-head team competition, and it is recommended that all first-year engineering courses based on this text should strive to include it.
The Accreditation Board for Engineering and Technology (ABET) sets curriculum criteria 3 that require students to have "an understanding of professional and ethical responsibility." In order to avoid creating this unintentional contrast between ethics and engineering, we have introduced a new pedagogical tool: . The rows of the matrix are the canons of engineering ethics and the columns are possible ways to resolve the problem. Each box of the matrix must be filled with a very brief answer to the question, "Does this one particular solution meet this one particular canon?" This is a structured approach that will bring discipline to this subject for first-year engineers. Each section in Part 1 has ethics problems pertinent to that particular section, and some with suggested answers given. We believe that it is more useful to infuse ethics continually during the term, than as a single arbitrarily inserted lecture.