2. Purpose It will require students to be able to perform structural analysis on two dimensional trusses. It will allow students to experience the creative process of design, which is the essence of engineering. The will soon realize that it is impossible to analytically produce an optimal design for a given set of requirements. A set of designs can be evaluated and compared against a given set of criteria, but the best of the set is not necessarily the best there is. They will come to understand the iterative nature of the design cycle. Students will learn a great deal about the terminology and history of truss bridges as they research time-tested standard designs. This project will teach students how the professional collaboration process works in the construction industry.
3. PA State Standards Science and Technology 3.2.12.D: Analyze and use the technological design process to solve problems. 3.4.12.C: Apply the principles of motion and force. 3.6.10.C: Apply physical technologies of structural design, analysis and engineering, personnel relations, financial affairs, structural production, marketing, research and design to real world problems.
4. PA State Standards (ctd) Mathematics 2.4.11.E: Demonstrate mathematical solutions to problems (e.g., in the physical sciences). 2.8.11.D: Formulate expressions, equations, inequalities, systems of equations, systems of inequalities and matrices to model routine and non-routine problem situations. 2.8.11.N: Solve linear, quadratic and exponential equations both symbolically and graphically. 2.10.11.B: Identify, create and solve practical problems involving right triangles using the trigonometric functions and the Pythagorean Theorem.
5. Objectives Student centered. On the spectrum of teacher to student centered, this project is at the extreme student end. Within the project, I will be serving the role of owner, for whom the design and construction teams work. As the owner my role will be to state the requirements for the bridges in terms of span, load, timeframe, cost, and aesthetics. It will be up to the students to satisfy these requirements.
6. Objectives (ctd) Learning and doing. We will spend some time prior to the project learning how to use the conditions of equilibrium in order to perform the analysis on a truss. Students will master these skills as they repeatedly analyze their designs. Students will also learn how to construct bridges on their own and will learn collaborative skills as they complete the project. This is a very “hands-on” project that will involve minimal direct instruction.
7. Objectives (ctd) Using information. Extensive resources on the design and analysis of truss bridges will be provided to students. It will be up to them, with the assistance of their teacher, to use these references to produce the best design. Historical references will also be available so that they can learn from the work of bridge designers before them.
8. Objectives (ctd) Facilitator. In addition to my role as owner as described above, I will, from time to time, trade hats to become the teacher in order to provide sufficient scaffolding to keep the project moving or to provide “just in time” teaching as questions arise.
9. Objectives (ctd) Multiple instructional and learning modalities to include all students. Students will learn visually as they look at their actual trusses and also as they “see” the difference between tension and compression members using the West Point Bridge Designer program. They will use auditory learning when they communicate with their team as they work on their design. Finally, the hands-on nature of bridge building will provide opportunities for motor learning.
10. Objectives (ctd) Higher order thinking skills. Students will apply the conditions of static equilibrium in order to analyze their trusses. They will synthesize what they know about trusses in order to produce a superior design, and they will evaluate each design they produce against the owner’s criteria.
11. Objectives (ctd) Interdisciplinary. Students will be using physics and math to analyze their designs. They will also examine the history of truss bridges. We will also use drafting software used in the industrial arts department.
12. Objectives (ctd) Collaboration. Each student will be a part of two teams: a design team and a construction team. The teams will each consist of two to three students. Students will collaborate both within and between their teams. The design team will depend on the construction team to implement their plans, and the construction team will depend on the design team for clearly communicating their design and construction procedures.
13. Objectives (ctd) Performance based assessments. Students will be assessed on both the finished product (the bridge) and on the process they used to create it. The bridge will be evaluated using owner-defined criteria such as load test performance, cost, meeting of deadlines, and aesthetics. The process elements will include the thoroughness of their analyses, their team contributions, and inter-team communications.
14. Objectives (ctd) Technology fully integrated into the classroom. Students will use technology throughout the project. They will use the internet to find the resources they need to complete the project. They will use the West Point Bridge Designer and drafting software to assist in the design of the bridge. They will also use technology to communicate between teams.
15. Objectives (ctd) Learning how to learn. Students will not be “spoon fed” information during this project. Aside from introductory material on Newton’s 2nd Law and the conditions of static equilibrium, students will be on their own, with the support of their teacher, to learn the details of the analytical technique of method of joints for truss analysis. They will also be learning how to design and construct bridges and use the particular software tools involved in this project. As is the case in life, they must take the initiative and know how, when, and from whom to ask for help.
16. Objectives (ctd) Students acting as a professional in the discipline. The project scenario will be very realistic in that project tasks will be divided between design and construction contractors. Students will be playing these roles in addition to designing and analyzing their trusses using technology. The design and analysis of the file folder bridge is no different than the process that would be used to design and analyze a wooden or steel truss bridge. Although students will be using technology such as the West Point Bridge Designer program and drafting software, they will not be using true “professional” software that would do too much of the thinking for them, defeating many of the learning objectives. After all, we still teach students their multiplication tables even though calculators can do this for us.
17. Timeline Week 1: Project introduction and construction and analysis of pre-designed file folder bridge found at bridgecontest.usma.edu. Week 2: Testing of member strengths to be used during truss design. Weeks 3-5: Design, analysis, and evaluation of at least three truss bridges by each design team. Week 6: Construction of selected designs by each construction team. Week 7: Inspection and sign off of completed bridges by design teams. Load testing of bridges and evaluation by owner. Week 8: Failure analysis and responsibility determination. Project reflection.
18. Components Inquiry: At various points during the project, students will be faced with a task for which they are unprepared, such as how to analyze a truss using the method of joints. This will generate a question in the students’ minds that they will pursue using online resources, textbooks, their peers, and their instructor. This inquiry process will guide the students’ learning of project objectives. Projects: The entire unit is essentially one giant project. Technology: Technology will be seamlessly integrated into the project as students use it for research, collaboration, and analysis.
19. Components (ctd) Flexible Grouping: Students will be working in both design and construction groups and will be grouped according to learning style inventory results. Authenticity: Although students will not be building actual bridges, the file folder bridges they make will look like miniature versions of the real thing and will incorporate many of the processes involved in construction of the real thing. The role-playing component in which design and construction responsibilities are divided between different teams will add to the authenticity of the project.
20. Resources File folder bridge construction materials: manila file folders wood glue razor knives rulers wax paper pins cardboard File folder bridge testing materials: compression member testing apparatus bucket sand
21. Resources (ctd) Technology hardware: laptop computers internet connection Technology software: West Point Bridge Designer 2005 Spreadsheet word processor web browser CAD program References: bridgecontest.usma.edu
22. Desired Outcomes Students will become experts at two dimensional truss analysis. Students will understand the ill-defined and iterative nature of design. Students will gain an understanding of the professional relationships that exist among various actors on a construction project. Students will improve their ability to organize and communicate their thoughts and work as a member of a team. Students will gain experience with software, such as CAD, with which they likely had no prior experience. Students will gain an appreciation of the economy of materials utilized by truss bridges and of the history and present-day status of the truss. Students will learn how to use resources made available by modern-day technology to meet daunting yet rewarding challenges.
