Beam Structure Optimization

The project

In Professor Muir’s fall 2025 design course, our team set out to design and manufacture a balsa-wood structure with the highest possible strength-to-weight ratio. We compared CAD concepts for structural performance and manufacturing feasibility, then developed the chosen design through finite element analysis, fabrication, and physical testing.

My contribution

I performed FEA on the selected structure to identify which members were likely to fail first and where additional stiffness was needed. I iterated on the geometry and beam sizes, helping turn the team’s initial concept into a stronger structure that could be manufactured with balsa wood and glue.

From question to method

• Compared our CAD concepts in terms of strength-to-weight ratio and manufacturing feasibility before selecting the structure to develop.
• Used FEA to identify vulnerable members, add stiffening features, and test different combinations of geometry and beam sizes. The final simulation produced a strength-to-weight ratio of 3,173.
• Designed the beam joints and calculated the end-cut angles to maximize contact area and improve the reliability of the glued connections.
• 3D-printed supports at specific angles to hold the beams in position during assembly and help the physical structure match the CAD model.
• Manufactured and tested the structure, achieving a physical strength-to-weight ratio of 2,845. Glue and additional joint material added weight beyond the idealized model.

Inside the project

Results & perspective

The final design achieved a simulated strength-to-weight ratio of 3,173 and a physical strength-to-weight ratio of 2,845. The difference reflected the added mass of glue and extra material at the joints, showing how fabrication details affect the performance of an optimized design.

What I gained

Taking the structure from CAD and FEA into fabrication and testing strengthened my confidence in tackling more sophisticated, real-world engineering challenges. I learned to consider joint geometry, adhesive application, and assembly accuracy alongside structural performance. This experience prepared me to approach projects shaped by practical constraints and customer requirements.