PBL module to design an “epic” tree house using finite element analysis.
In this project-based learning experience, students are asked to design and optimize an artificial tree trunk to support an “epic” treehouse for a fictitious, eccentric but innovative, Aunt Ada. It was implemented in a Strength of Materials course at Lehigh University to a class of 52 students in their second, third, or fourth year. This module may be suitable for use in a Strength of Materials class or any finite element analysis class. The project has both individual and team based assignments completed outside of class. When implemented, it took a total of two 50-minute class periods dedicated to assignment explanations and team discussions spread over the course of five weeks.
The module has a total of five parts including defining parameters, writing pseudo code for a finite element analysis, creating a design proposal, and completing a 1D finite element code and analysis. It is suggested to modify this project in the future to be condensed into three parts. This project provides a platform for exploration of some of the course learning objectives in an experiential format; furthermore, a number of in-class active-collaborative exercises support the project and further enhance the course content.
1) Determine both normal and shearing stresses in simple beam and beam like structures; utilize stress analysis information to design application specific beam cross-sections (here, normal stress only),
2) perform 1D stress/strain analysis utilizing the finite element method,
3) construct a computer code to implement a finite element solution for a one-dimensional rod of
4) compute critical buckling load for columns subject to different fixations (i.e. boundary conditions),
5) account for column weight in computing critical buckling load.
If finite element analysis is not part of a course’s typical coverage but an instructor desires to expose students to discretized methods for solving integrals, then additional lecture time for this topic must be budgeted.
Much is left open-ended in this project so instructors must decide how much supplementary information should be given to the students, when the information should be shared, and how it should be disseminated.
If a code is sought from students, instructors must either ensure that students have necessary prerequisite coding skills or spend further lecture time on coding.
Instructors must decide if lecture time will be surrendered to allow for student team presentations. This can be a lively way to end the project.
The module assignments should be condensed to have three parts instead of five parts.