Our materials, although we were not allowed to add any additional materials, we had a green light to create prototypes of both designs by reusing some old foam board.
We divided our groups, myself and Dieudonne have worked on my idea, Doug and Pedro would work on Doug's idea whilst Rhia and Sophie were taking pictures and recording the events that took place throughout the build, they have also helped in each design by suggesting new ideas in regards to technique and application of materials into the construction.
Both Dieudonne and I began to work on my idea, the I beam supported span. My aim was to build a deck that would be 150 mm wide and 1600 mm long, underneath it would be a set of foam boards positioned vertically, that way the foam tensions resistance is greater than if it would be positioned flat, this would just make it bend at its weakest spots. The diagram on the left shows how the load will affect the material and the tensions within it.
This is the kind of technique I tried to apply in my initial idea. Both dieudonne and began to create the prototype under the supervision of Sophie and Rhia.
The main focus of mine and Dieudonnes work was to attach the pieces to the bottom of the deck, We used scissors in to make holes through which we put through the rope in order to make a system that will hold the deck and supporting foam board together like so...
What the system consists of is mainly a rope that will go through the two pieces and create a "T" like structure. we would have double the middle section as the centre of the element appeared the most vulnerable to me. The deck would be 150mm wide as it allow us to make two stripes from each board 50mm x 800mm to be used as support. We positioned two boards next to each other creating a span of 1600, the other piece of foam would be positioned on top of the two,
On the left is our prototype being tested to until it shows signs of failure. We now have made the centre really strong but the ends of the centre support now became the weak points where the construction seemed to fail. Christian, Rhia and Sophie all worked really hard to help us generate the a solid support and get rid of the vulnerable points. We have come up with two ideas to improve the build.
Christians idea of making the construction more stable.
Our new team member who we met today has suggested that we lengthen the centre support as it appeared to be very strong by attaching the four panels to the ends of the centre support.
So once we made the connection right away we have increased the strength of our bridge, the ends of each support lines attach to the centre support whereas the ends that are positioned on the table are separated, this has given us a lot more stability.
Sophie's suggestion of making the bridge stronger
She has suggested that we would keep the element turned upside down in order to create a stronger the structure. Reason being is that the support panels are divided into three sections, when they are on the bottom of the design the dead weigh of the platform separates the panels away from each other, whereas when they are positioned upside down the panels actually press into each other, giving us just a little more strength.
We have decided to keep the spam upside down, one concern that Rhia pointed out was that the platform on which the weigh will be positioned for testing needs a solid support as it will be impossible to balance the platform on thin part of foam board in the centre, as you can see on the picture above.
-------------------------------------------------------------------------------------------------------------------------
Doug's Idea of the element spanning the gap.
Just as we finished making the prototype we have gathered together to discuss the pros's and con's of the prototype of our alternative idea, alternative for a reason because that's when I saw Doug's prototype, it was a great idea, right away it showed me the standard of knowledge and application second year student have on this course. Doug's idea was pretty much a master piece...
Shortly after seeing this design we all dropped our stuff and tried to help building this structure, each taking various roles like piercing and making knots to hold the joints, cutting the foam, brainstorming ideas and also sharing our thoughts and implementing it into the design.
As each joint had a knot on it, this would give additional support to the foam to prevent it from falling apart from each other. There would be two of those on each joint, Eight in total.
It was difficult to make the knots really tight as the rope was very close to the foam and tying it was pretty hard as the rope kept stretching out, making the joints very loose.