Standards and Codes in
Mechanical Engineering Education

• Confounding Constraints or
  Helpful Hindrances?

"Conventional View of Engineering Education": Badly-dressed, nerdy young men with crew cuts, wearing horn-rimmed glasses, getting their hands dirty while using strange looking laboratory apparati, being taught by stuffy professors at chalkboards… Right?

Well, this image may reflect the norm of the 1960s engineering student, but in the late 20th century, engineering education is far removed from that conventional view of almost 40 years ago. A "Modern View of Engineering Education" might be one of smartly-dressed, savvy young women working in virtual laboratories being taught in electronic classrooms by professors conscious of educational theory.

What exactly is engineering education? One definition might be "the pedagogical demonstration of the practical application of mathematics and science in the implementation of engineering principles to the solution of societal problems." The invocation of standards and codes in engineering education might almost seem stifling to the learning experience of modern engineering students. After all, why would an educator confound or hinder students by limiting their fresh and creative engineering solutions? The answer of course lies within the original definition of engineering education: "...the practical application of mathematics and science..." Standards and codes are consensus documents that allow engineers to implement engineering principles for the solution of societal problems consistently, safely, economically, and efficiently. Thus, the constraints of standards and codes do not hinder students, but instead help define practical limits on their designs.

In the author’s experience as an engineering educator in a mechanical engineering department at a major research university, standards and codes are playing increasingly greater roles in modern engineering education both inside the classroom and outside of it (i.e., in independent study or research projects). In modern engineering education, the direct exposure of students to the practical application of standards and codes as an integral part of the curriculum can help students retain up to 90 percent of the course material (as opposed to only 10 percent retention if the material is only read). Indeed, the Accreditation Board for Engineering and Technology (ABET), has included reference to standards and codes (that is, "engineering standards and realistic constraints") in the new accreditation requirements for the 21st century, "Engineering Criteria 2000."

In-Classroom Experiences
In the mechanical engineering curriculum at the University of Washington, undergraduate students are exposed to standards and codes at two levels: implicitly, through overview courses on design, and explicitly in courses that use standards and codes directly as part of the course content. The following examples illustrate these levels of exposure.

The course "Introduction to Mechanical Design" (ME395) provides students with their first formal description of design as a systematic methodology (that is, design as an iterative decision-making process subject to functional requirements and performance constraints). This formal concept of design is sometimes disturbing to students who heretofore have thought of design as a free-form creative enterprise unfettered by restrictions (natural or induced).

In the context of ME395, standards and codes are discussed as follows:
Standards--The term "standards" has many implications. To the researcher and the technical community it may mean fundamental test methodologies and units of measure. To the manufacturer or end-product user, standards may be materials specifications and tests to meet requirements. Commercial standards are the rules and terms of information transfer among designers, manufacturers, and product users. There are even fundamental differences between levels of standards: company (internal use with only internal consensus), industry (trade/project use with limited organizational consensus), government (wide usage and varying levels of consensus), and full-consensus (broadest usage and greatest consensus).

Often case studies are provided giving examples of the use of standards and standards-writing bodies such as the American Society for Testing and Materials (ASTM), Society of Automotive Engineers (SAE), etc. Examples of the use of standards are illustrated by citing their usefulness and indespensibility in daily experiences (i.e., weights and measures, fasteners, etc.).

Design Codes--The meaning of the term "design code" is not generally well understood. Often, a design code is not a design manual (that is, a "cookbook" design procedure resulting in a desired component or system). Instead, design codes are widely-accepted, but general, wide-ranging rules for the construction of components or systems with emphasis and constraints on safety. A primary objective is the reasonably certain protection of life and property for a reasonably long safe-life of the design. Although the needs of users, manufacturers, and inspectors are recognized, the safety of the design can never be compromised. Finally, unlike standards, which may be implicitly included in design codes but which provide no rules for compliance or accountability, design codes require compliance through documentation, and certification through inspection and quality control.

In the classroom, examples of the importance of design codes include the fact that they may even be backed as legal requirements for implementing an engineering design (for example, certification and compliance with the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code is a legal requirement in 48 of the 50 United States). The Uniform Building Codes carries legal implications in many municipalities and states.

"Mechanics of Materials Laboratory" (ME354) and "Manufacturing Processes" (ME355) are two courses in which standards and codes are used explicitly. For example in ME355, ASTM Standard E 18, Test Method for Rockwell Hardness and Rockwell Superficial Hardness of Metallic Materials, is used by students to evaluate the Rockwell hardness of heat-treated steel alloys. As follow-on exercises in both ME354 and ME355, ASTM Standard E 8M, Test Methods of Tension Testing of Metallic Materials [Metric], and E 646, Test Method for Tensile Strain-Hardening Exponents (n-Values) of Metallic Sheet Materials, are used to evaluate the effects of heat treatment and the effects of material type on monotonic tensile stress-strain response. ME354 often uses ASTM standards not only directly in laboratory exercises (for example, E 8M), but also as reference documents for further analysis of testing results (for example, E 646).

In ME354, a range of laboratory exercises involve students in the pedagogically-proven "see, do, say" regime of the cone of learning, which can achieve up to 90 percent retention of course material. The "see" portion comes from classroom or laboratory demonstrations. The "do" part comes from students conducting actual laboratory experiments. The "say" part is the laboratory report, sometimes in worksheet form and sometimes as a formal engineering laboratory report.

One example of such an exercise is the "Structures Lab" in which a bicycle frame is used to challenge students with the question "When is a truss not a truss?" A strain-gaged bicycle frame is examined experimentally. An analytical model of the truss-like bicycle frame is studied. Finally, a numerical model (finite element analysis (FEA)) of the bicycle frame is evaluated. Aspects of various standards and codes are used throughout this exercise. Thus, students learn during in-class exposure to standards and codes that, rather than being confounding hindrances to engineering practice, standards and codes actually provide helpful constraints to design and analysis.

Outside-the-Classroom Experiences
Both undergraduate and graduate students benefit from outside-the-classroom exposure to standards and codes. Some case studies of students involved in such projects under the author’s supervision are presented as follows.

During his junior year in mechanical engineering, Guy Faubion became interested in standards development while taking a predecessor course to ME354. As part of several consecutive quarters of undergraduate independent study, he successfully took the lead in two different task groups of ASTM Committee C-28 on Advanced Ceramics, drafting the initial documents for standard test methods for compression testing monolithic and composite ceramics. Although he graduated with his BSME before these documents were approved as ASTM standards, he did stay active in the task groups, evaluating comments from various ballots and helping to incorporate changes into the evolving draft standards. The approvals of ASTM C 1358, Test Method for Monotonic Compressive Strength Testing of Continuous Fiber-Reinforced Advanced Ceramics with Solid Rectangular Cross Sections at Ambient Temperatures, and C 1424, Test Method for Monotonic Compressive Strength of Advanced Ceramics at Ambient Temperature, led to the presentation of an Award of Appreciation to Guy by Committee C-28 in recognition of his leadership efforts in standards development while an undergraduate engineering student.

Engineering design "per the code" can be daunting work even for an experienced practicing engineer. Nonetheless, as a senior mechanical engineering student, Keith Johnson was intrigued by his initial industrial exposure to the ASME Boiler and Pressure Vessel Code while working on a pressure vessel for ARCO Products Corporation as a summer intern engineer at Anvil Corporation. He proposed to conduct an undergraduate independent study project to confirm the design of a vertical tower pressure vessel per the Code. In particular, the required shell and head thicknesses were calculated. The nozzle support pads and vessel supports were also designed. During the course of this project, Keith was encouraged to apply for the prestigious D.J. McDonald Memorial Scholarship administered by the National Board of Boiler and Pressure Vessel Inspectors. Backed by a strong endorsement from the Department of Mechanical Engineering, but more importantly substantiated by his excellent academic and professional background combined with his application of the ASME Boiler and Pressure Vessel Code, Keith was one of two recipients nationwide of this $5000 scholarship in 1997. Keith’s interest in standards and codes provided not only academic but also financial rewards.

Graduate students have also been involved in use and development of standards through their masters and doctoral research. Over the past seven years, six out of 15 graduate students under my supervision have verified or evaluated ASTM standards as part of their research projects. Most recently, Paul Van Landeghen was the primary participant at the University of Washington in a four-part multi-laboratory round robin program that established, among other things, precision and bias statements for three ASTM standards: C 1275, Test Method for Monotonic Tensile Strength Testing of Continuous Fibre-Reinforced Advanced Ceramics with Solid Rectangular Cross-Section Specimens at Ambient Temperatures, C 1292, Test Method for Shear Strength of Continuous Fibre-Reinforced Advanced Ceramics at Ambient Temperatures, and C 1341, Test Method for Flexural Properties of Continuous Fibre-Reinforced Advanced Ceramics. Paul tested 10 specimens of a commercial ceramic composite for each type of test (in-plane tension, in-plane flexure, in-plane shear, and interlaminar shear) for a total of 40 tests, including the application of multiple-strain gages on each specimen, in addition to the usual preparations for testing. As part of his thesis, Paul not only analyzed and presented his intralaboratory results but also the interlaboratory results. In so doing, he compared his results to the other participants. He was able to propose draft precision and bias statements for C 1275, C 1292, and C 1341. This effort resulted in not only a comprehensive master of science thesis but also open literature publications as well. Paul’s research experience gave him first-hand appreciation of why ASTM standards are synonymous with the descriptions "comprehensive" and "technically rigorous."

Summary
The inclusion of standards and codes in modern engineering education is not only ongoing, but is essential for preparing future engineers to play successful roles in their profession. Experience has shown that incorporating standards and codes into "see, do, and say" classroom/laboratory exercises gives students a better understanding and stronger retention of these essential aspects of engineering practice. Development, verification, and refinement of standards and codes in both undergraduate and graduate independent study and research projects have been highly successful in utilizing the unique and particular talents and resources of individual students. Thus, standards and codes in engineering education provide helpful constraints to avoid confounding and hindering student learning.

Acknowledgment
For many of the photographs and the applications aspects of this article, the author expresses his appreciation to the faculty, staff, and students of the Department of Mechanical Engineering at the University of Washington.

Bibliography
Accreditation Board for Engineering and Technology, "Criteria for Accrediting Engineering Programs," ABET, Baltimore, Maryland, 1998.
D. Arola, P. G. Reinhall, S. C. Iverson and M. G. Jenkins "An Experimental Analysis of a Hybrid Bicycle Frame," Experimental Techniques Vol 23, No 3, 21-24, 1999.
M. Jenkins and D. Arola, "When Is a Truss Not a Truss? An Undergraduate Laboratory Exercise Involving the Experimental, Analytical and Numerical Study of a Bicycle Frame," submitted to Journal of Engineering Education 1999
B. I. Hyman, Fundamentals of Engineering Design, Prentice Hall, Upper Saddle River, New Jersey, 1998.
M. G. Jenkins, Mechanics of Materials Laboratory University of Washington, Seattle, Washington, 1997.
J. R. Farr, "The ASME Boiler and Pressure Vessel Code: Overview", pp 1-34 in Pressure Vessel Codes and Standards, Elsevier Applied Science, 1983.
P. L. Van Landeghen "Intra- and Interlaboratory Round Robin Mechanical Test Evaluation of a Continuous Fiber Ceramic Composite (CFCC)" M.S. Thesis, University of Washington, Seattle, 1999.
P.L. Van Landeghen and M. G. Jenkins, "Comparative Investigation of Intra- and Interlaboratory Mechanical Tests of Flexure, Tensile and Shear Behavior in a CFCC," Ceramic Engineering and Science Proceedings V 20, No 3, in press, 1999.