Tribology courses in a mechanical engineering curriculum

Tribology courses in a mechanical engineering curriculum

173 Wear, 38 (1976) 173 - 175 @ Elsevier Sequoia S. A., Lausanne - Printed in the Netherlands Short Communication Tiibolo~courses in a mechanical ...

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173

Wear, 38 (1976) 173 - 175 @ Elsevier Sequoia S. A., Lausanne - Printed in the Netherlands

Short Communication

Tiibolo~courses

in a mechanical engineering curriculum*

N. S. EISS and M. J. FUREY Department Blacksburg,

of Mechanical Engineering, Va. 24061 (U.S.A.)

Virginia Polytechnic

Institute

and State

University,

(Received November 5, 1975)

Tribology concepts are introduced to the students in mechanical engineering at Virginia Polytechnic Institute and State University in two ways: as a topic in a course, or as a complete course devoted to certain phenomena in tribology. The concept of the friction force is introduced in the second year course - the mechanics of solid bodies. The emphasis is on the friction force as one component of a force system acting on a solid body, but the concepts of the adhesive and ploughing components are introduced. In the course on mechanical design the selection of anti-friction (rolling element) bearings based on fatigue life and the design of hydrodynamic bearings using the Raimondi and Boyd design charts are presented. In a graduate course on fluid flow, Reynolds’ equation is developed from the Navier-Stokes equations. Certain tribology concepts may also be introduced in problems in the fourth year design courses, the most frequent concept being the selection of anti-friction bearings. The courses in the curriculum which totally concern tribology are an undergraduate (fourth year) elective course in tribology, and two graduate level courses: friction and wear, and lubrication. The undergraduate course has been taught in its present format for only one year. In previous years, the course was entitled Industrial Lubrication and the syllabus was devoted to properties of lubricants and the study of some industrial lubricating systems. The current course is an introduction to the basic tribological concepts in friction, wear and lubrication. The student is introduced to the important elements that affect a lubricating system: materials of construction, operating conditions, lubricant properties, machine design, and methods for producing surfaces. This approach helps the student to see the diverse nature of the field of tribology and increases the possibilities for him to solve lubrication problems successfully. Theories of friction and wear are presented as *Contribution to papers presented at the 3rd International Tribology Conference “Tribology for the Eighties”, Paisley, September 22 - 25, 1975.

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well as the fundamentals of boundary lubrication, additive chemistry and elastohydrodynamic lubrication. Over one-third of the fourth year students elected to attend this course. While some were disappointed because it was not applied enough, the majority felt that the course was worthwhile. The graduate level course on friction and wear starts with the history of friction and wear and then covers surface characterization and theories of friction and wear. The major objectives of the course,are to introduce the theories and discuss their relative acceptance, and to acquaint the students with the literature in the field of tribology. To accomplish this last objective, several references are given for each topic covered. Sometimes references with conflicting conclusions are included so that the students will have the opportunity to weigh the reported evidence and make their own conclusions. A second method used to accomplish this objective is to assign a research paper for which the student must select a topic, read at least three references and then summarize the data and conclusions, adding his own critical commentary. The graduate course on lubrication has two major objectives: to stimulate discussion of the physics and chemistry of lubrication and to develop an approach to solving lubrication problems. The first objective includes discussion of areas which are known and can be explained by existing theory, areas known experimentally but not yet understood, and some important questions that need to be answered. The emphasis in the course is on the functions of the lubricant, e.g. to reduce friction or to reduce wear and surface damage, and the properties of the lubricant which contribute to the accomplishment of these functions. Major topics include hydrodynamic and EHD lubrication, solid lubricants and experimental and analytical techniques. -4s in the friction and wear course, published literature is used extensively in support of lecture material, as a source for research papers, and to acquaint the student with the sources of literature. An important part of the course is the project, which is usually a research paper based on published papers. Occasionally, some students do experiments related to their industrial jobs and report on the results. While our tribology courses occasionally attract a student from another engineering or science curriculum the majority of our students are from mechanical engineering. The courses in the mechanical engineering curriculum are highly problem oriented. The topics covered in the tribology courses are largely based on empirical data and what little theory exists is of an elementary mathematical nature (with the exception of hydrodynamic and EHD lubrication and heat flow from rubbing surfaces). Hence the courses deal more in concepts than in problem solving. We have found that it is most important to inform the students of this fact at the beginning of the course so that their expectations of the course correlate with the objectives of the course. Because these courses involve a variety of disciplines, some students are reluctant to sign up for the courses. They prefer to stay with courses in familiar and traditional mechanical engineering subjects such as thermody-

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namics, fluid flow, machine design and heat transfer. Hence it is often necessary to recruit students by making presentations to prospective students prior to the quarterin which the courses will be offered. Once in the courses, students are generally satisfied and some elect to work on our tribology research projects.