TIJ1O_truss

= = //Truss Design and Build Challenge//
 * Truss-Buster**

Overview
Studying trusses (when hand-framed they're called rafters) is an excellent way to learn many things. They reflect an ongoing understanding of building materials and the physics of loads. Rafters and trusses tell us what people know about design and manufacturing processes. Trusses incorporate the use of very basic design principles but are usually constructed in ingenious and complex ways. Special materials are used in trusses to make them strong and long lasting. Sometimes even trusses are exposed to view as part of an architect's design plan. For the student just starting to understand design principles and how technology plays in our lives there is no better place to start than by studying trusses.

The Challenge
You will design and build a truss able to span a distance of 60cm and support a dead load, at its midpoint, of 5 lbs (plus the bucket weight of 2 lbs) for 20 seconds. After this initial requirement, further testing to destruction will continue with increments of 5 lbs. being applied.

Specification
1. You will be given 8 m of “scaled 2x4’s” (scaled: 4 mm, 9 mm) pine wood. 2. Only wood glue may be used. 3. The pitch of the roof may be no greater than a 45 degree slope (a ’12 pitch’ roof) 4. The testing device will be top loaded on the roof. It will disperse the weight evenly over the surface of the trusses. 5. Once a wood joint fails, the roof truss will have said to have failed and the competition is over for your team. 6. You will be evaluated as a portion of the winners’ load to weight ratio. 7. The roof MUST fit onto a 60cm by 45 cm ‘top plate’ for testing. 8. Minimum competition weight is the empty bucket for 20 seconds.

Note: Construction can only take place in the classroom.

Materials
- scaled “structural 2x6” (6mm x 12mm) - PVA glue

New Terminology
1) Research the following words and give definitions for each.
 * Beam
 * Compression
 * Deck
 * Top Plate
 * Span
 * Stress
 * Tension
 * Torsion
 * Truss
 * Roof Pitch

2) In your design report include the results of research of 3 truss types and give the advantages and disadvantages of each. An excellent internet resource site may be found at: [] []


 * Things to turn in and/or have evaluated:**
 * **Component** || **Value** ||
 * 1 - Sketches || 4 ||
 * 2- CAD drawing || 10 ||
 * 3 - Truss construction || 10 ||
 * 4 - Practicality of design || 10 ||
 * 5 - Testing || 10 ||
 * 6 - Peer review || 4 ||
 * 7 -Technical Report || 10 ||


 * **CATEGORY ** || **4 ** || **3 ** || **2 ** || **1 ** ||
 * **Sketches ** || Drawings are flawless - pullouts (notes) include relevant design details || Drawings are good, pullouts are included. Mostly all details are addressed. || Generally the drawing conveys design plans. There are several design elements missing. || Many design elements are missing from the drawing, but overall the design can be understood. ||
 * **AutoCAD File ** || Relevant views of the there are clear || All views are present, though there may be confusion in the drawings || Generally the drawings can lead towards a final product, but there are flaws in which construction details may be obscured || There are large errors in the object views - such that construction will be difficult based on the schematics. ||
 * **Truss construction ** || <span style="font-family: Arial,sans-serif; font-size: 12px;">Construction of the product is superior. All joints and cuts are careful and deliberate. Product is stylistically superior. || <span style="font-family: Arial,sans-serif; font-size: 12px;">Construction is sound. Cuts and joints may not all be perfect. Product is generally pleasant to look at. || <span style="font-family: Arial,sans-serif; font-size: 12px;">Generally the construction is solid. Cuts and joints as well as style all leave something to be desired. || <span style="font-family: Arial,sans-serif; font-size: 12px;">The construction is weak. Joints and or cuts are mismatched which results in a stylistically inferior product. ||
 * **Truss**
 * practical design** || Construction is elegant, yet simple and uncomplicated. Labour costs would be low as a result which increases profit. || Design is well planned, but perhaps more complicated than it should be. || Because the design is more complicated than it should be, labour costs are likely higher than they should be. Design could, and should, be easier || Design is not well thought through, no matter how sturdy. ||
 * **<span style="font-family: Arial,sans-serif; font-size: 12px;">Technical Report ** || <span style="font-family: Arial,sans-serif; font-size: 12px;">All aspects of the report are present and exemplary || <span style="font-family: Arial,sans-serif; font-size: 12px;">All aspects of the report are present, though may require some work || <span style="font-family: Arial,sans-serif; font-size: 12px;">There are aspects missing and work is required || <span style="font-family: Arial,sans-serif; font-size: 12px;">There are many flaws in the report ||
 * **<span style="font-family: Arial,sans-serif; font-size: 12px;">Use of Time ** || <span style="font-family: Arial,sans-serif; font-size: 12px;">Used time well during each class period (as shown by observation by teacher, and documentation of progress in journal) with no reminders. || <span style="font-family: Arial,sans-serif; font-size: 12px;">Used time well during most class periods (as shown by observation by teacher, and documentation of progress in journal) with no reminders. || <span style="font-family: Arial,sans-serif; font-size: 12px;">Used time well (as shown by observation by teacher and documentation of progress in journal), but required reminders on one or more occasions to do so. || <span style="font-family: Arial,sans-serif; font-size: 12px;">Used time poorly (as shown by observation by teacher and/or documentation of progress in journal) in spite of several reminders to do so. ||

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__ Peer Review Sheet __

Your name:

Partner’s name: (unequal)--- (completely equal) 0- 1 -- 2 -- 3 -- 4 -- 5
 * Both members participated equally in the design and building of the project
 * Ideas were listened to and considered respectfully

(respectful environment)--- (ideas were shot down) 0- 1 -- 2 -- 3 -- 4 -- 5

How was the partnership equal/unequal? How would you change workload for next time?


 * [[image:big_blank_box.png]] ||

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