This year, I set a goal to take a larger role in the structural design of our Formula SAE car. In past seasons, node placement in the chassis was often justified qualitatively, which limited our ability to predict stiffness and refine suspension geometry. After discussing with our chief engineer, I began developing a quantitative method to evaluate chassis stiffness node by node.

I wrote a MATLAB program that integrates with Fusion 360 to calculate and visualize node deflection. The program imports node coordinates, constructs local stiffness matrices for each connecting member, and assembles them into a global stiffness matrix. Each node is modeled with pinned connections except the one of interest, which remains free. The global system is reduced to a 3×3 stiffness matrix for that node, and by solving F = K·u, the program outputs deflection under a unit force rotated 360 degrees around the node.

The result is a three-dimensional deflection plot that provides quantitative insight into chassis compliance. This method replaces hand-wave justification with clear, repeatable data, strengthening our design process. While I am still working on automating Fusion 360 integration, I have tested the program on last year’s chassis to validate the workflow and prepare for the 2025–2026 car.