Battle of the Bridges - Quad City Engineering and Science Council

6 th Annual QCESC/ASCE Battle of the Bridges Fri-Sat, February 8-9, 2013Rules, Tools, Materials2012 “Battle of the Bridges” video @ http://www.youtube.com/watch?v=gMgBjHBjcfo&feature=youtu.beObjective:Location:Category:Cost:Schedule:Prizes:Sponsors:To build a model bridge onsite given a box of materials provided at the workshop within a timelimit of 3 hours that is capable of supporting the greatest load per unit of mass.The Putnam Museum1717 West 12 th StreetDavenport, IA 52804The contest is open to any student, grade or age for either Friday or Saturday. The primaryreason for the Friday session is to raise HS team participation as this is the first event of threefor the QC Tech Challenge. A team may consist of one, two, three or four people. All membersof the team must be signed up on the registration form.ALL team members must know their team name @ registration! Elementary (Grades 4-6) Middle School (Grades 7-8) High School (Grades 9-12)College (Ages 18-22, or enrolled in post-secondary degree program)Family (Any combination – kids, adults, seniors)Registration limitations:Friday: 36 teams max (any combination) limited to 9 teams from any one High SchoolSaturday: 36 teams max (any combination), limited to 9 High School teams only$25.00 per team. The cost includes a bridge kit and a complete tool kit provided to you at theworkshop, popcorn & pop. The cost does not include entrance to the museum and/or theatre –not required for event. Scholarships are available upon request to the Putnam Museum.Registration Deadline – Thursday, February 7th, 2013. The registration form and further detailsare available at www.qcesc.org by 12/21/12.If you have any questions, please contact Jeff Melvin @ director@qcesc.orgOR The Putnam Museum’s Alice Loff @ 563-324-1054 ext. 266 www.putnam.orgFriday: check-in/setup 11:30 AM - Noon, Bridge Building 12:15-3:15 PM,Load Testing 3:15-4:45 PM (awards on Saturday only)Saturday: check-in/setup 7:30-8:00 AM, Bridge Building 8:15 - 11:15 AM,Load Testing 11:45 AM -1:15 PM, Awards for all categories 1:30-2 PM* Saturday teams will be able to pre-purchase pizza, to be delivered ~11 AM; consult the on-lineregistration for details. Sack-lunches are allowed to be eaten in the Grand Lobby.Bridges with the highest structural efficiency (E = maximum load / bridge mass) will be awardedprizes in each category (1rst, 2 nd , 3 rd ) with a “Most Innovative” judged from all.Quad City Engineering and Science Council (QCESC)American Society of Civil Engineers (ASCE)PCT Engineered SystemsWestern Illinois University School of EngineeringSaint Ambrose University - EngineeringSociety of American Military Engineers (SAME)The Putnam MuseumUniversity of Wisconsin - PlattevilleTownsend EngineeringAshton EngineeringExelon Nuclear – Quad CitiesPage 1 of 6

6 th Annual QCESC/ASCE Battle of the Bridges Fri-Sat, February 8-9, 2013Rules, Tools, MaterialsBridge Building Guidelines:1. Prior to the Battle of the Bridges contest, we encourage you to explore on the internet other bridgecontests, bridge building tips or at the very least consider some of the guidelines provided below. Thiswill help you generate ideas prior to contest day. The material and tool lists will be available 12/19/12 @www.qcesc.org – you are encouraged to experiment during the two weeks before the event.A 10-minute tutorial will be given before the 3-hour “build” session; Engineers will be available toanswer questions.2. See pages 5 & 6 for ASCE bridge building basics. Some excellent websites to begin generating ideas,learn more about bridges, bridge building and other bridge contest are listed below:http://www.bridgesite.com/funand.htmhttp://www.instructables.com/id/Popsicle-Stick-Bridge/http://www.garrettsbridges.com/category/popsicle-bridges/http://andrew.triumf.ca/andrew/popsicle-bridge/(free software) West Point Bridge Designer 2012 @ http://bridgecontest.usma.edu/download.htm3. For additional bridge ideas look around at real bridges. Remember that for a real bridge, the importantpart is not the deck that the cars drive on, but the steel or concrete structure that supports the deck.4. Your bridge needs to have a solid, stiff shape in all 3 dimensions. Engineers call this “maximizing themoment of inertia” of your structure. For example, take a Popsicle stick on its flat side and have itoverhang from the edge of a table. Then, apply a bit of force with your fingers at the loose end andnotice the deflection of the stick. Now, try the same thing; but, this time place the stick on its edge andtry to bend the stick now. Notice how the stick is much stiffer and stronger when on its edge?5. A bunch of sticks glued together flat, like a raft, has very little strength and will sag during testing undervery little load.6. The strongest structural shape is the triangle. A bridge which is made of a series of triangles will bevery strong.7. A bridge that is symmetrical is less likely to twist when loaded and will probably carry more load.8. Bridges which are built too tall will have a high moment of inertia (which increases stiffness andstrength – a good thing); however, they may become unstable under a load (a bad thing). This maycause your bridge to twist or topple to one side and…well, you can guess.Bridge Contest Rules, Testing and Evaluation:Bridges are designed and built by Civil Engineers, who are guided in their work by the rules of physics, buildingcodes and a code of ethics. Building codes are based on public health and safety. Fairness is the basis of acode of ethics, which guides Engineers to treat their clients and competitors fairly and respectfully. The rulesof this competition reflect building codes and engineers’ codes of ethics.Note: QCESC will inspect each bridge prior to weigh-in to verify compliance1. Teams will build bridges within a time limit of 3 hours, on site, using a box of materials provided at theworkshop. Each team should have as its goal to build a bridge that is capable of supporting thegreatest load per unit of mass of bridge material. Each team should perform its own work, both designand construction. The team may ask the contest judges for suggestions. NO pre-constructed bridgecomponents are allowed to be used, even for modeling – written plans ARE permitted.2. Tools: each team will be provided a standard set of tools, to be turned in to the QCESC prior to leavingthe building area for testing. No tool, whole or in part, may be built into the bridge itself.Page 2 of 6

6 th Annual QCESC/ASCE Battle of the Bridges Fri-Sat, February 8-9, 2013Rules, Tools, Materials3. Bridge models will be loaded at the middle of the span. Care should be taken in the design to reinforcethis area as well as the end supports with bracing. The load, supplied and applied by the judges, shallhang from the bridge. The load will be applied downward, from below, by means of a rectangular plate(approximately 6”x1”x1/8” thick) resting on the loading plane of the bridge. The loading plate will beparallel to the axial axis of the bridge at the time of load application. The plate will have an eyeboltattached from below at its center. Weights will be suspended from this eyebolt. Bridges must bedesigned to accommodate the loading apparatus.4. The weight of the bridge will be recorded prior to testing, after inspection by the QCESC (see #11)5. The load shall be increased until the bridge fails. The largest load will be recorded for each bridge.6. The bridge will be judged based on the highest efficiency rating (E = maximum load / bridge mass).7. Testing will consist of the application of an increasing load until the bridge breaks. The peak loadrecorded up to this point will be considered the breaking load.8. Bridge length: maximum 24-inches; minimum 19-inches. Bridge must span a gap of 18-inches (a wood“fixture” is provided to each team to model this 18-inch span).9. Bridge height: 9” max above the deck, 9” max below the deck; combined total above and below = 12”10. Bridge width: maximum 6 inches; minimum 4 inches. Must have deck system across the entire portionof the bridge that spans the 18-inch gap between supports.11. The bridge deck must be able to support a weighted toy truck (~3” high, 2.5” wide, ≤ 5 lbs.) as it isrolled the entire length of the bridge – to verify that the bridge acts as a bridge.12. In the event of a tie or multiple bridges with the same efficiency rating, the lightest bridge wins. It is upto your team to decide on the optimum balance between mass and strength.13. Judges will be provided by the contest sponsors. All decisions of the judges are final.14. The rules will be finalized and posted @ www.qcesc.org not later than 12/19/12 for this competition.Be creative and have fun!! ! We look forward to seeing you build your amazing bridges!Note: Photos taken by the QCESC or its agent are the property of the QCESC – release forms will need tobe signed at the Putnam Museum the day of the event.Pre-Weigh-In Bridge Inspection Checklist:Bridge length: maximum 24-inches; minimum 19-inchesBridge spans a gap 18-inchesBridge height: ≤ 9” above deck, ≤ 9” below deck, ≤ 12” totalBridge width: maximum 6 inches; minimum 4 inchesDeck system across the entire portion of the bridge that spans the gapDeck capable of supporting weighted toy truckAssembly area inspected before team tests their bridgeAcceptable?YYYYYYYPage 3 of 6

6 th Annual QCESC/ASCE Battle of the Bridges Fri-Sat, February 8-9, 2013Rules, Tools, MaterialsTOOLSOnly tools provided by the QCESC may be used during this eventNo “tools” are allowed to be included (whole or in part) in the final bridge to be tested.1/2 Round FileYardstickMini-pliers w/ wire snipsNitrile (non-latex) glovesCoping saw6” Utility CalipersClothespins (~30 per team)Utility knifeCutting boardWood Fixture (to mimic the span)8” Triangle Carpenter SquareBRIDGE BUILDING MATERIAL KIT(Available at craft/hobby/hardware stores throughout the Quad Cities)Glue – three - 4 gram tubes of Loctite p/n 39202 Quicktite Gel or equivalent Ethyl CyanoacrylateString (small ball)Masking Tape (available upon request)Roadway PiecesPoster board 21x3 1/4" 1 eaPopsicle Sticks5 7/8 x 3/4 x 1/16" 120 ea4 1/2 x 3/8 x 1/16" 80 ea5 1/2 x 1/4 x 1/16" 80 eaWood PiecesRound Dowels - 36" x 1/8" 2 eaSquare Dowels - 36" x 1/4" 2 ea24" x 3/16" 2 ea(This LOCTITE is the widely available equivalent)Page 4 of 6

Bridge Building BasicsTYPES OF BRIDGES:Arch Tied Arch Basket Handle ArchSuspensionTrussCable StayLOAD PATH:COMPRESSION +TENSION - Strengthen areas where loads are concentrated (Load Point and Abutments)CONNECTIONS: Bridges are only as strong as their connections: Reinforce JointsPage 5 of 6

STABILITY: Use triangular shapes to prevent rectangles from leaning Compression members such as the Top Chord will try to buckle sidewaysduring loading. Prevent by using bracing such as Top Lateral Bracing. Think about stability in the width direction of your bridge. Prevent twistingby using a "closed" shape such as a box or triangle as opposed to an "open"U-shape.EXAMPLES OF TRUSS TYPES:Page 6 of 6