Experience Gained in Teaching Computer Aided Design
Using a Problem Centered Learning Approach
Erol Inelmen
Bogazici University
Education Faculty
Bebek, Istanbul, TURKEY
Tel: +90 212 263 1540/1788
inelmen at boun.edu.tr
Abstract
The experience gained by the author after teaching Engineering Graphics for three decades now is shared in this paper with the hope that peers will contribute in enhancing the contents and the methods so far implemented. The introduction of computer aided design software has provided an opportunity for newing the challenge the adminstration has posed by accepting the requirements of the accreditation board. The requirement to increase the design content of the courses to %25 has been a challenge that was overcomed by the use of the ACAD software package. Students hopefully are better equipped now to visualize the engineering objects with the use use of exploded, mesh and isometric drawings so easy to create using computer aided tools. Unfortunately time restrictions have forced the instructors to reduce the contents of the course. Classical topics such as geometry, lettering and auxiliary views are now ommitted and students performance on paper work has dropped as compared with the outcomes in previous years. To increase the level of motivation in the students and the instructor a “project centered learning” approach has been recently introduced. Students are required to prepare a unique project that is graded based on weekly progress reports. Person to person contact in the development of the projects assures full participation. Classwork is only a means to check the performance of students while new concepts are introduced.There has been a warm welcome to the changes from the part of young members of the staff. Now that the use computer aided tools are rapidly expanding, it remains now the challenge for a full integration of this course. The possibilities of using the same principles implemented in “finite element analysis” -is the in our opinion- the key in the process of integration. Students should feel that graphics is an integral part of the process for adquiring the necessary skills in preparing successfull engineering designs.
Keywords: project based learning, finite element analysis, computer aided design software, curriculum integration
INTRODUCTION
Having introduced the art of engineering graphics to freshmen students using the traditional drafting tools for three decades, the author is facing the challenge of introducing of computer aided design in his new courses. This new approach in engineering design is requiring changes in the semester program which are at times painful and at times very rewarding (UNESCO, 1998). In this paper the author makes a self-assessment of the experience gained during this change with the hope of sharing the results with other practicioners aiming at improving the contents and methods of education as we enter the new millenium (Kar and Yilbas, 1995). The following sections explain the environment and the conditions in which the changes are taking place aiming at better understand the nature of the changes and make a more accurate assessment. Results of some the early implementation is presented, the paper concludes with suggestions for a full integration of the engineering undergraduate curriculum (Yerlici, 1987)
BACKGROUND
The university where the author is currently affiliated –now a public institution- continues to keep closely and firmly the tradition of the former American Robert College founded in 1863. Consequently engineering practice is still based on the methods and standarts implemented in the north of the new continent. It is worth mentioning that local codes are based on the same standarts as in many other countries in Europe. This practice -which is also shared with only a couple of other local universities- provides -among other many important advantages- the assurance of the ability to adapt to technological changes. Another important condition that should be clarified is the fact that the very popular Autodesk computer aided design package was adopted after an extensive selection process. This particular program is not the best one when dealing with sophisticated engineering problems.
The course in Engineering Graphics is designed to suit the needs of the individual departments –civil, industrial, chemical, mechanical, electrical and computer-. Unfortunately -due to administrative reasons- it is not always possible to have an homogenous class. This fact results in conflicts in the selection of the topics that will best appeal to all members of one particular class. Recently the university administration has decided to start the accreditation process which is currently implemented in the new continent. During the process of assessing the course contents, the need to increase the number of hours spent in engineering design -thus reducing the science contents whenever possible- became apparent. The need to add more hours for design has encouraged the author to introduce design hands-on- experience to the engineering graphics course resulting in an increase in the number of hours spent in the so called working drawings (Inelmen, 1998).
As a consequence of adding more emphasis to working drawings, some minor details –such as fastening, spring and key- had to be removed from the program. Another important change was the introduction a a new text book having more emphasis on computer aided design and using the same software adopted by the administration. Students were supposed to make up for the changes by just reading through the book. Encouraged by the progress the students were making the author introduced for the first time the requirement to make an “exploded drawing”. This change made it possible for the student to better visualize the compliance problems that emerge when parts are to be assembled. The most recent addition to the program was the use of boxes to generate the mesh drawings in three dimensions, with the aim at introducing students to the exciting world of “finite element analysis”.
While introducing the computer aided design approach, an important issue that the author had to face was the need not to relay completely on the new tools. It was suggested to the students that engineers develop their ideas faster on paper by making sketches. To consolidate this idea student were invited to the civil engineering department laboratories to draw –both at the beginning and the end of the course- equipment there available. Students where able to assess by themselves the progress they have made during 13 weeks -of 3 hours per week- practice. Alternating one week of drafting on the table and one week working on the computer, aimed at mastering of the classical and the modern methods of design as much as possible. It was nevertheless clear that students were not willing to work on paper and compared with other years outcomes, -since the chapter on geometry and lettering had to be omitted- the quality of the lines on paper has dropped considerably.
Although special effort have been made to overcome the problems the students have in visualising the object they have to draw, this continues to be an important issue that needs further consideration. Drawing artifacts available in the mechanical laboratory of the Physics department helped to some extent in improving the situation. Students were first asked to draw the artifacts free hand in-situ as it is to be expected in real life cases. The sketches were then used to make a proper draft on paper that continued with the implementation on the computer. Using three dimensional tools –surfaces and solid drawing- available in the computer software students were better encouraged to see their shortcomes while drawing somewhat complex objects.
Since some years the author has noticed that althought the available text books in the market are very comprehensive, students do not like to prepare themselves for classwork. The implementation of the project requirement assured to some extent that students prepare themselves and attend carefully the short lectures given at the end of each week. Giving a homework same to all students has never been a solution to the problem of encouraging practice. On the other hand the assignment of unique project to each student assures that there is a person to person contact while dealing with the minor details of the solution (Lehto, 1998). Since the outcome of a project cannot be predicted at the time of the launching of the exercise, much patience is required on the part of the instructor in dealing witht the feelings of panic that arise (Kelly, 1970). To cope with the difficulties in project development, weekly progress reports must be expected and promptly reviewed with comments and graded.
RESULTS
The computer laboratory recently furnished for freshmen students having a network system provided the instructor with the possibility of following the progress of the student while in class from the monitor provided in the front of the class. The large number of students -being 30 this year in each session- has prevented the instructor from making real time comments to each individual student on their performance (Inelmen, 1998a). Only some general comments -such as center line use, implementation of layers for better understanding of the design, need to show dimensions without overcrowding the drawing- were made verbally in class hopefully keeping the level of enthusiasm as high as possible. Technical difficulties caused by malfunctioning of the computer resources must be dealt with diplomacy and mutual understanding must be developed to cope with cases ending in the loss of data. Never should classes be extended over the allocated time slot – 105 minutes being the best- when dealing with computer work.
Although it is necessary to accept that there exsists a high degree of subjectivity while evaluating the performance of the design work of students, it is a important to be as accurately and fairhanded as possible. A close look at the figures given in the Appendix of this paper –selected among the work of 59 students for the 6 project weeks allocated during one semester - is helping in evaluating the outcome of the different measures implemented to enhance the hands-on experience. It remain to see how the INTERNET facilities already available in the laboratory can be used to improve the level of motivation of the students. Since cooperative work in real time is possible using this modern facilities there is window of opportunites that still remain to be explored. Students were encouraged to surf in the pages of the LEGO toy company to search for fascinating technical solutions.
The course outline given at the beginning of the course in a web page, included the subjects on projections, sections, dimensions, explosion/assembly in two and three dimensions. The most exciting experience was the introduction of the “mesh problem” a natural consequence of the possibilities of using LEGO toys that was envisaged at the beginning of the course. The fact that each subject was covered twice –once as a plate and once a computer work- accounts for the 14 weeks of the semester. It remains to integrate in this newly emerging practice in design, the addition of a comprehensive knowledge of engineering materials and shop practice that students unfortunately lack at this stage of the curriculum (Inelmen, 1998b).
Since computer language is a prerequisite for the use AUTOLISP –a programming facility very popular in the professional life- this feature has not yet been implemented. Students consequently loose the benefits of having an exciting experience in experimenting with the parametric design power of the software. It remains as a challenge for the author to reduce the time it take to explain the basic features of the program by using the copy of the main screen annoted with the brief explanation of the menus available. This document –prepared by the staff of the university which is now available in the INTERNET- which was shown at the beginning of the course hopefully will enhance the quality of the explanatory lectures.(see attached figures)
CONCLUSION
It is too early to assess the benefits that will be seen from the changes made in the outline of the Engineering Graphics course offered by the author in the university -which is at the same time his alma mater- he is currently affiliated. We are expecting more cooperation on the part of the peers in integrating the contents of this course with the contents of the other courses the students are expected to take in the future years. The introduction of concept -if not the theory- of Finite Element Analyis and its implementation in making “meshed drawings” has been cautiously welcomed by the other younger instructors. There still a lot to do to remove the barriers between the different departments. Robotics which is definetly a newly emerging discipline –our university hosting the UNESCO Mechatronics Chair- may be an adequate catalizer in the process of integration (Kaynak and Sabanovic, 1994). Although each engineering department may have a different expectation from the Engineering Graphics course, they should all unite around the idea that automation is and will be the most powerful ingredient in future designs.
ACKNOWLEDGMENT
The support of Dr.Zenon J.Pudlowski Director of the UICEE is acknowledged.
REFERENCES
Kaynak M.O. and Sabonovic, A., (1994) “Diffusion of New Technologies Through Appropriate Education and Training” presented at the Diffusion of New Technologies Conference, St. Petersburg.
Kar, A.K. and Yilbas, B.S., (1995) “Reengineering the Engineering Schools”, presented to The Fourth Saudi Engineers Conference, Jeddah.
UNESCO, (1998) “Learning: The treasure within”, Unesco Publishing, Paris.
Kelly, G.A., (1970) A Brief Introduction to Personal Construct Theory, In: Bannister, D. (ed.) “Perspectives in Personal Construct Theory”, Academic Press, London., 1-29.
Yerlici, V., (1987) “An interdisciplinary approach to engineering curriculum, Proceedings of the 16th International Syposium, International Society for Engineering Education (IGIP), Leuchtturm-Verlag, 512-516.
Lehto, S., (1998) “New solution for world engineering education in the 21st century: fom from the outside mass driven teaching to internally-driven individual learning by means of an optimised process of real-world learning projects, In: UNESCO Global Congress on Engineering Education, Z.J.Pudlowski (Ed.), Cracow, Poland, 387-382.
İnelmen, E., (1998a) “Experience gained in implementing modern management concepts in the classroom”, In: ISSWOV, 6. International Conference on Work Values and Behaviour, İstanbul, 116-120
İnelmen, E., (1998b) “Introducing freshmen students to hands-on experience in engineering design”, In: UNESCO Global Congress on Engineering Education, Z.J.Pudlowski (Ed.), Cracow, Poland, 273-276.