In Mechanics of Solids and Structures, my team created two bridges, one out of popsicle sticks and one out of spaghetti strands. Both bridges were analysed theoretically through hand calculations, SolidWorks simulations and Instron testing. They were then tested to failure. The first bridge, from spaghetti, held 37 pounds with a strength to weight ratio of 41. The second, made with popsicle sticks held 110 lbs with a strength to weight ratio of 166.
Spaghetti Bridge:
From research, we determined that the best design for a point loaded bridge was an arch with radial tension members. We simulated this through building compression members that were large enough to prevent buckling and attaching tension members at the joints between compression members. Individual members were built using 3D printed forms. To analyse the design, we solved the truss in matlab and used theoretical buckling calculations to determine the strength of the individual members.
Popsicle stick Bridge:
After the success of our spaghetti bridge, we used a similar design, except we replaced the tension members with string due to limits on the number of popsicle sticks that we could use. The compression members were made up of popsicle stick T beams. This bridge was analysed through testing individual members and comparing that to a force analysis done in SolidWorks. The report can be read below.
Spaghetti Bridge:
From research, we determined that the best design for a point loaded bridge was an arch with radial tension members. We simulated this through building compression members that were large enough to prevent buckling and attaching tension members at the joints between compression members. Individual members were built using 3D printed forms. To analyse the design, we solved the truss in matlab and used theoretical buckling calculations to determine the strength of the individual members.
Popsicle stick Bridge:
After the success of our spaghetti bridge, we used a similar design, except we replaced the tension members with string due to limits on the number of popsicle sticks that we could use. The compression members were made up of popsicle stick T beams. This bridge was analysed through testing individual members and comparing that to a force analysis done in SolidWorks. The report can be read below.