2. GK12 Review Presentation
C.J. DeGroot
St. Louis Charter School

3. Three Units Designing and Building File-Folder Bridges
Build a Model Truss Bridge
Test the Strength of Structural Members
Analyze and Evaluate a Truss
Hazard Mitigation Letter
Tsunami Brochure

4. Designing and Building File-Folder Bridges
Brief introduction to engineering
What is engineering?
What do engineers do?
What type of people are engineers?
What different types of engineering exist?
What things do engineers work on?
Types of Engineering

5. Designing and Building File-Folder Bridges
Learning Objectives: Build a Model Truss Bridge
Identify different types of bridges
Explain what a truss is
Identify the major components of a truss bridge
Identify types of truss bridges
Explain fundamental engineering concepts:
Force, Load, Reaction, Equilibrium, Tension, Compression, Strength
Explain how a truss carries load
Explain the roles of owner, design professional, constructor, project manager
Explain how construction quality affects structural performance

6. TeachEngineering.org Activity
Tension or Compression?
Write down if the items indicated in the following pictures are in tension or compression

7. Tension or Compression?
1. Chain of a swing

8. Tension or Compression?
2. Leg of a swing set

9. Tension or Compression?
3. Leg of a desk

10. Tension or Compression?
4. Bike Chain

11. Tension or Compression?
5. Spoke

12. Tension or Compression?
6. Arm

13. Tension or Compression?
7. Arm

14. Tension or Compression?
8. Tennis Ball

15. Tension or Compression?
9. Racket Strings

16. Tension or Compression?
10. Shoelace

17. Tension or Compression?
11. Clothes in a full suitcase

18. Tension or Compression?
12. Kite string

19. Tension or Compression?
13. Power lines

20. Tension or Compression?
14. Tripod legs

21. Tension or Compression?
15. Spring

22. Tension or Compression?
16. Truss member DK

28. Designing and Building File-Folder Bridges
Learning Objectives: Test the Strength of Structural Members
Calculate cross-sectional area of a member
Describe yielding, rupture, and buckling failure
Explain the factors that affect the tensile strength and compressive strength of a member
Design a testing program to determine the strength of structural members
Explain the principle of the lever and apply it
Determine the tensile strength and compressive strength of structural members experimentally
Use a computer to analyze and graph data

29. Principle of the Lever Forces must be balanced
Moment must be balanced around the fulcrum

33. Tensile Strength Graph

34. Compressive Strength Graph

35. Designing and Building File-Folder Bridges
Learning Objectives: Analyze and Evaluate a Truss
Calculate the components of a force vector
Add force vectors
Explain fundamental engineering concepts:
Free body diagram, equilibrium, structural model, symmetry, static determinacy, stability, factor of safety
Use the Method of Joints to calculate the internal force in truss members
Determine the strength of every member
Evaluate a truss to determine if it can safely carry a given load

36. Add Force Vectors

37. Add Force Vectors

38. Add Force Vectors

39. Method of Joints

40. Hazard Mitigation Letter
Learned about structural and nonstructural earthquake mitigation (focused on nonstructural)
Learned Mitigation Techniques for:
Computer Equipment - Gas shut-off valves
Hot water heaters - Windows
Pictures and Mirrors - Flexible gas lines
Bookcases/cabinets - Chimneys/Masonry
Light Fixtures - Securing heavy objects
Library stacks - Signs/Bulletin boards
Securing heavy equipment

41. Hazard Mitigation Letter
Learned what to do before, during, and after an earthquake
Broke into two groups for “inspecting” the school
Each student was responsible to write a persuasive letter about how the school could be made safer through earthquake mitigation techniques

42. Tsunami Brochure
For the globalization requirement, we studied the 2004 Indian Ocean Tsunami
Students chose a particular country to focus on
Students were responsible for their own research
Amy and I provided guidance (no Wikipedia, etc.)
Students each made a three-panel informational brochure with Microsoft Publisher
Information about tsunamis
Information about their country
Information about rebuilding in their country