Popsicle stick bridge Ryan and Simon

Introduction Unit of Inquiry: Bridge Unit “Can I span the distance?” Statement of Inquiry: How do design limitations encourage creativity in technology? Mission: Make a Popsicle stick bridge with the following specifications Max 75 Popsicle sticks Max 3 sticks of glue Min 30 cm length Max 20 cm superstructure Max 20 cm substructure Goal: Create a Popsicle stick bridge using the sticks and glue to make a structure that can hold itself up and extra load

Research Triangles have the best shape in building bridges as the force pushed down from top is equally spread because of the triangles shape We found that a shorter bridge can hold more weight Also, A very well executed bridge makes the weight distribute properly We learned some basic principles regarding bridges like tension and compression compression tension

Investigating bridge design We started possible designs on the bridge we were to create. We worked on some variants of the truss bridge, and a design of the arc bridge We sought to implicate as many triangular shapes as possible We added lots of pros and cons to help us decide on which bridge to use.

Investigating bridge design 2 We decided to try to see how many popsicles sticks we needed for certain and came up with ideas for our sides, top and bottom parts to our bridge We laid them out and counted the popsicle sticks and discussed thoroughly weather to put certain sticks in, or to use it somewhere else, where it could be more useful

Starting creation process We finally decide to make our bridge a variant of the upside-down truss Ryan and I decided to do a variant of the upside-down truss We laid out our paper design and started to glue our sides first For some parts of our bridge, we decided that the naturally rounded edge of the popsicle stick would not be efficient, so we cut the tips off at an angle so that it would be snugly fit between sticks

Creation progress As we continued to glue our sticks together, we came across a problem called racking, this is because we had little support across our bridge sides Racking is when the bridge strains or stretches violently, and in our case the bridge was very weak and prone to inwards collapse because of the lack of structure. Right side up Upside-down

Final Creation Our final creation looked like this We had added many extra diagonal beams Extra glue in important joints Tried to have 2 supporting beams across our bridge at the ends to prevent it from collapsing inwards We were confident in our bridge to at least beat 50 lb.

Applying research into creation (Triangles) We know that triangles is the strongest shape, and therefore, we tried to implement it as much as possible

TESTING DAY We were very hyped to see how much weight our bridge could hold. Ryan and I didn’t really set a goal weight, but we agreed that it would probably hold over 50lb.

Looking back thoughts We reflected by realizing that our top to bottom connecting structure was not strong, in fact, we didn’t have one! Next time, we agreed to have a more central based structure, so it doesn't snap in half as it did But we fulfilled our guesses, and our bridge manage 60lb. :D

Simon’s Reflections I discovered that our bridge failed due to a lack of structure, and if we were to build another bridge we would probably use stronger glue, and add more layers to our frame. I also thought that our bridge would do better if we used our couple last popsicle sticks to support our weak joints, and we could cut them into smaller pieces to support some parts of the lengths of the bridge. Overall, our bridge was successful, but could’ve been better in gluing and joint placement.

Ryan’s Reflections I feel that our bridge lacked support in the center maybe we could have added a popsicle stick down supporting the center of the bridge . Or we could have changed up the design more that would have been more focused on spreading the weight. Overall our design worked well but with a few minor changes could have done a lot better.

Responsibilities Powerpoint – Simon 70% - Ryan 30% Bridge – Simon 40% - Ryan 60% 4 design idea paper – Simon 60% - Ryan 40%

Bibliography http://cdn.instructables.com/FT4/NCXR/FT17YI80/FT4NCXRFT17YI80.LARGE.jpg http://trianglesinbridges.weebly.com/uploads/2/5/0/3/25039113/52568_orig.jpg