机械工程专业英语文本2

6 Engineering Design工程设计Engineering design is a systematic progress by which solutions to the needs of humankind are obtained. The progress is applied to problems (needs) of varying complexity. For example, mechanical engineers will use the design process to find an effective, efficient method to convert reciprocating motion to circular motion for the drive train in an internal combustion engine; electrical engineers will use the process to design electrical generating systems using falling water (落水)as the power source; and materials engineers use the process to design ablative(烧蚀性的) materials which enable astronauts to safety reenter the earth's atmosphere.The vast majority of complex problems in today's high-technology society depend for solution not on a single engineering discipline(工程学科), but on teams of engineers, scientists, environmentalists, economists, sociologists, and legal personnel. Solutions are not only dependent upon the appropriate applications of technology, but also upon public sentiment(公众意见) as executed through government regulations and political influence. As engineers we are empowered with the technical expertise to develop new and improved products and systems, but at the same time we must be increasingly aware of the impact of our actions on society and the environment in general(总体的) and work conscientiously toward the best solution in view of all relevant factors.Design is the culmination(最高阶段) of the engineering educationalprocess; it is the salient(突出的) feature that distinguishes engineering from other professions.A formal definition of engineering design is found in the curriculum guidelines(课程指导) of the Accreditation Board for Engineering and Technology (ABET). ABET accredits(鉴定) curricula in engineering schools and derives its membership from the various engineering professional societies(行业协会). Each accredited curriculum has a well-defined design component which falls within the ABET guidelines. The ABET statement on design reads as follows(内容如下):Engineering deign is the process of devising a system, component, or process to meet desired needs. It is a decision making process (often iterative 重复性的), in which the basic sciences, mathematics, and engineering sciences are applied to convert resources optimally to meet a stated objective(目标、目的). The engineering design component of a curriculum must include most of the following features: development of student creativity, use of open-ended problems, development and use of modern design theory and methodology, formulation of design problem statements and specifications, consideration of alternative solutions, feasibility considerations, production processes, concurrent engineering design, and detailed system descriptions. Further, it is essential to include a variety of realistic constraints such as economic factors, safety, reliability, aesthetics, ethics, and social impact.If anything can be said about the last half of the twentieth century, it is that we have had an explosion of information. The amount of data that can be uncovered on most subjects(学科) is overwhelming. People in the upper levels of most organizations have assistants who condense most of the things thatthey must read, hear, or watch. When you begin a search for information, be prepared to scan many of your sources and document their location so that you can find them easily if the data subsequently appear to be important.Some of the sources that are available include the following:1.Exisiting solutions. Much can be learned from the current status of solutions to a specific need if actual products can be located, studied and, in some cases, purchased for detailed analysis(购买进行详细分析). An improved solution or an innovative new solution cannot be found unless the existing solutions are thoroughly understood.2.Your library.Many universities have courses that teach you how to use your library. Such courses are easy when you compare them with those in chemistry and calculus(微积分), but their importance should not be underestimated(低估). There are many sources in the library that can lead you to the information that you are seeking. You may find what you need in an index such as the Engineering Index(工程索引). There are many other indexes that provide specialized information. The nature of your problem will direct which ones may be helpful to you. Don't hesitate to ask for assistance from the librarian. You should use to advantage the computer databases found in libraries and often available through CD-ROM (C ompact d isc-r ead o nly m emory)technology.3.Professional organizations.The American Society of Mechanical Engineers is a technical society that will be of interest to students majoring(主修) in mechanical engineering. Each major in your college is associated with not one but often several such societies. The National Society of Professional Engineers is an organization that most engineering students will eventually join,as well as at least one technical society such as the American Society of Civil Engineers (ASCE), the Institute of Electrical and Electronic Engineers (IEEE), or any one of dozens that serve the technical interests of the host of specialties with which professional practices seem most closely associated. Many engineers are members of several associations and societies.4.Trade journals(行业杂志). They are published by the hundreds, usually specializing in certain classes of products and services.Money and economics are part of engineering design and decision-making. We live in a society that is based on economics and competition. It is no doubt true(勿容置疑) that many good ideas never get tried because they are deemed to be economically infeasible. Most of us have been aware of this condition in our daily lives. We started with our parents explaining why we could not have some item that that we wanted because it cost too much. Likewise, we will not put some very desirable component into our designs because the value gained will not return enough profit in relation to its cost.Industry is continually looking for new products of all types. Some are desired because the current product is not competing well in the marketplace(市场). Others are tried simply because it appears that people will buy them. How do manufacturers know that a product will be popular(畅销的)? They seldom know with certainty. Statistics(统计学) is an important consideration in market analysis. Most of you will find that probability(概率论) and statistics are an integral(组成的) part of your chosen engineering curriculum. The techniques of this area of mathematics allow us to make inferences(推论) about how large groups of people will react based on thereactions of a few.。