Truss Bridge

Course

March 2025

The goal of this project was to design and fabricate a lightweight wooden truss bridge that could withstand significant load relative to its own weight. The target was to maximize the load-to-weight ratio by applying concepts from Mechanics of Deformable Solids and iteratively improving the design through analysis and testing.

- Design & Analysis: Simulated the truss bridge using the Truss Simulator (JHU Engineering Innovation) to optimize geometry and member dimensions, iterating through 15+ truss designs to identify the most efficient structure.

- Design Iteration: Fully modeled three truss bridge designs in AutoCAD, refining geometry through multiple iterations and preparing AutoCAD files to ensure accurate fabrication with laser cutting.

- Assisted in brainstorming and structural calculations to predict potential failure modes, including dowel bending, plate tearing due to shear, and member failure, in order to estimate the bridge’s load-bearing capacity.

- Fabrication: Contributed to laser cutting and assembly of wooden members to create a precise and lightweight structure.

- Design Modifications: Improved the bridge performance by:

- Adding spacers on the dowel to distribute load.

- Increasing the distance between the edge of the member and the dowel hole.

- Increasing member thickness to delay shear and bending failures.

- Collaboration: Participated in brainstorming sessions to refine the truss design and select improvements that balanced strength and weight.

- Conducted three experimental tests, showing progressive performance improvements.

- Increased the maximum supported load from 5.5 kg to 7.5 kg, while keeping the bridge mass at 13.9 g.

- Achieved a significant improvement in load-to-weight ratio, from 392.86 to 543.48.

- Strengthened practical skills in structural design, Autocad, fabrication, and failure analysis.