REVISITING THE MODULUS CONCEPT IN MECHANICAL ENGINEERING DESIGN TEACHING

In teaching machine design it is not only important that students are given logical problem solving processes or stress analysis evaluation techniques but also a practical sense of proportion, design for purpose and an understanding from which models can be developed. Although computer aided design techniques and sophisticated simulation packages assist engineers there is a growing impression that students are becoming out-of-touch with physical understanding and ultimately at risk of arriving at design solutions which do not address the fundamental design problem in an appropriate manner. This is not good engineering practice and an attempt to avoid such results should be taught as early as possible within an engineering degree. This paper looks at some common problems arising with current engineering students and the education system that may give rise to them. It then revisits the modulus concept in engineering design and its applicability in mechanical engineering and also the possibility of re-teaching it to the cohorts. The modulus concept is based on experience and a relationship to key attributes. Learning by observation of existing machine parts and design solutions helps part way in achieving this. It also assists in developing models for calculation purposes and a sense of proportion and physical understand helps check results/solutions. It is an appreciation of these simple aspects that this paper hopes to achieve. To do so, it provides a brief historical review of the modulus concept in machine design, pointing out the fluctuation in its appreciation over time and draws attention to its appropriateness for today’s engineer. These concepts appear to be familiar in architecture degree however not so common in mechanical engineering. Starting from a convenient choice of the modulus, the progress of the design process is somewhat more straightforward. The paper concludes with some examples that may be used nowadays to help convey this idea to the students