Design Process

Define the Problem

• We have to create a Pratt Truss bridge that is as cheap as possible but is also has a compression force that does not exceed 0.4 and a tension force that does not exceed 0.45.

Generate alternative concepts

• We created multiple designs using Bridge Designer and modified them to lower the overall price. Some bridges we made were not Pratt-Truss Bridges, but we used their designs to create other bridges which met the project's requirements.

Evaluate and select a concept

• We chose the Bridge Designer model that met the given requirements with the sturdiest design. By lowering the height of some beams, we were able to use less materials and lower the cost.

Detail the design

• After completing our Bridge Designer model, we converted it to a similar model in Model Smart 3D and made the necessary changes for it to meet the length requirements. We decided to add extra members to the center of the bridge and it helped increase the total weight that it could support.

Design defense

• Our design is good since it passed a load test of 1,250 pounds when the weight was centralized, and it had a maximum load capacity of 1,950 pounds when weight was distributed between ten of the joints.

Manufacture and Test

• Using TinkerCAD, we modeled a prototype that was checked then 3D printed through Polar3D to produce a physical copy of our design.

Evaluate Performance

• Our online bridges met all of the requirements and were able to hold a decent amount of weight.