Fuselage April-May Gusset Revisions
Throughout our design process we’ve encountered several tricky “gusset problems” where many beams on different planes converge at a critical structural joint. As with any design challenge, there are always multiple ways to solve the same problem. By basing our designs on those which have been in use for nearly forty years, we can reduce the risk of designing something that works in theory but not in practice. As discussed in our Landing Gear Design Part 3: Revisions post, one of the key gusset problems we had difficulty solving was that of the landing gear. In short, our previous landing gear design was too complex and relied on being attached to the already busy lower cabin beam clusters making it very difficult to gusset together. After we adjusted our landing gear design based on Graham Lee’s Nieuport 11 design, we were able to repurpose his gusset design and solve this gusset problem.
Graham Lee Nieuport 11 Truss Frame and Gussets Credit: Frank Geiger
Our Graham Lee Inspired Gusset Solution
Another tricky gusset problem we struggled with was the infamous empennage cabin gusset. This gusset is located on the intersection of the cabin and the empennage and will be one of the most stressed joints in the entire airplane due to the large forces generated by the long lever arm of the empennage. We experimented with several different designs but weren’t quite satisfied with any of them. They would either put the gusset rivets in tension or rely on bending super thick aluminum sheet metal which isn’t practical or safe. The solution eventually came when we took a step back and reapproached this problem with a different lens. We had been visualizing the joint as the intersection of two slightly truncated rectangular and triangular pyramids. In this way, we were focusing on the pyramid’s differences and intersection point rather than their similarities and intersection area. Also, we had been studying existing gusset designs in such detail over the past week that we often found ourselves recreating and mimicking existing designs which didn’t help in this situation. When we took a break and re-approached the problem, we quickly realized that, despite the differing base geometries of the pyramids, it would be relatively easy to make them both share a plane on one face. This would then allow us to use two thick, flat gussets to connect the two. Looking back, this solution seems easy and almost obvious. We learned a lot about gusset design and collaborative design throughout this process but the real lesson we took away from our gusset problems was one of design thinking. We realized that sometimes a fresh perspective and some out of the box thinking is the most valuable tool at hand. Had we continued to study and remix existing designs we may have never come to the solution we had and only by taking a step back and rethinking our own thought process were we able to succeed in the end.
An early attempt at the gusset problem using a thick bent aluminum plate
Our new gusset solution. Note that only unique parts are pictured so some gussets appear missing. These will be added in when we create an assembly.
*Editors' note: the thought processes and design choices presented in this article don't necessarily represent those implemented into the final design and are subject to change. Flight Club Aerospace is a group of amateur students with no formal education in any fields of engineering. We present this information for educational purposes only, with the understanding that it is not to be re-created without adequate professional oversight and mentorship. For our latest designs and updates, please see our most recent blog posts.