BRIDGE PROJECT

SUMMARYSamantha Crytser

And Delores Ferguson

Period.11

Bridge Breaking Video

WHAT WENT WRONG AND HOW OUR BRIDGE BROKE: Our bridge broke where the center and

the gussets from the sides of bridge the gussets just pulled apart the arches and the sides stayed intact.

If I could go back in the building process I would forgo the corners on the bottom of the bridge . I would have tripled you the arches and reinforces the middle section of the bridge that was holding the sides together.

STRESSES ON THE BRIDGE On our bridge there was strain, simple

stress, shear tress, tension, compression all acting on our bridge when we tested our bridge.

CHANGES TO DESIGN

When we originally designed the bridge we were going to triple up the archesAnd put a smaller arch on the bottom where the corners are now. We found that you could not bend the arches enough to do what we planned and if we had tripled up the arches we would have run out of wood. As for the middle we did our best to gusset and strengthen the two sides together by doing cross support as well as pieces going straight across.

COMMON FAILURES OF OTHER BRIDGES: Not all of the bridges had the same

weakness but the majority of them broke where the bridges ends touched the block the wood just pulled apart there or in other bridges cases such as ours the middle is what broke for the most part the sides stayed together they middle and the sides simply separated.

EFFICIENCY In our opinion the simple reinforced arch

design with supports was most efficient. It had more strengthen and stability and I believe it distributed the weight more evenly.

TIPS FOR BUILDING BALSA WOOD BRIDGES: Gusset everything and when you build

really think about the strength of what the support do.

And most importantly do be afraid to use to much glue and if you are building an arch bridge make sure you triple or quadruple the arches with a strong middle.