A Project Based Introduction To The Finite Element Method

All mechanical engineering majors at the Naval Academy are required to take a course in Computer Aided Design during their senior year. The underlying philosophy of the course is to introduce students to computer based solution techniques that are currently used in engineering practice. To emphasize the utility of the computer the problems selected for solution are ones that would be difficult to solve by hand. In particular, students are introduced to the finite element method through a project requiring the design of a bracket that must meet size, load, and deflection requirements. In addition, the strength to weight ratio of the bracket is to be optimized. The students are given a brief introduction to the fundamentals of the finite element method, including basic theory and practical guidelines for modeling. Then design teams are formed to design and build the brackets. The brackets are tested to check the performance against the design requirements, to compare the teams predicted results to actual performance, and to see which team achieves the highest strength to weight ratio. The IDEAS software package is used to generate the geometry of the bracket and to perform the finite element analysis. Design teams have developed brackets with strength to weight ratios of 6000 and have been able to predict failure loads to with 10% of the measured value. This project-based approach to the finite element method gives the students an appreciation for how powerful the method can be in performing structural analysis.