Manufacturing and validation of 3D printed space structures via multiaxial testing

Since its first apperance in 1999, the CubeSat standard has made access to space more affordable and easier for small realities such as universities and research institutions. The cost of a CubeSat already dropped a lot thanks to the availability of Off The Shelf components, but the structure is still an expensive part if you want it customized. A viable option to reduce its costs and increase customization is to produce it using Additive Manufacturing methods. Following this introduction, in the first part of the thesis, the author has designed two different 1U CubeSat structures that have then been manufactured using the Fused deposition modelling (FDM) process. In particular the structures have been printed using PEEK, a material that can and has already been used in space. The two structures differ in approach, one follows a more classic design similar to the ones already in use in the industry and the other is designed trying to use in the best way possible the advantages that Additive Manufacturing offers. Rigorous testing is crucial for ensuring space structures can withstand the harsh launch environment. One of the most critical factors to consider is the vibration experienced during launch. The forces acting on the launch vehicle and satellite are predominantly multi-directional and random in nature. However, traditional vibration testing methods typically rely on single-axis excitation, failing to fully capture the complex vibration modes of the satellite. In contrast, Multi-Input-Multi-Output (MIMO) testing approaches are capable of more accurately replicating the realistic multi-dimensional vibration environment encountered during launch. This enables a more comprehensive evaluation of the satellite's structural integrity and failure modes, leading to improved design and qualification for the actual launch conditions. In the second part of the thesis the author focused on creating an environment as similar to reality as possible using a 4-DOF shaker that allows the object to be subjected not only to all three translations but also one rotation. This was done in primus by using the same profile, in terms of excitation, that is already used for the single axis testing and using it for all three translations. Then the author tackled another problem: the use of a CLA (Coupled Load Analysis) environment as target. The problem in recreating this environment on a multi-axial shaker is given by the difficulty in making the table recreate that environment, in particular the rotations, using only linear accelerometers. This thesis gives a procedure to solve this problem and that can be used in other situations. In general the author wants to give almost a full look on what a CubeSat structure history looks like before being launched into space, from the design to the testing.