In order to simulate the conditions of high altitude flight we must either buy or build our own thermal-vac chamber. Since commercial ones cost more than $10k, we will be designing, and building our own low cost thermal-vac chamber.
The Thermal Vacuum Chamber concept consists of single 1/4“ thick aluminum tube with a 7.5” ID and 8.0“ OD. We then place a 1/4” aluminum plate on one end and 1/2“ acrylic on the other end. We will also add a hole on the bottom aluminum plate to allow wires to pass. All joints are sealed with low temperature liquid gasket.
Tubes available here: https://www.speedymetals.com/pc-4661-8371-8-od-x-250-wall-tube-6061-t6-aluminum.aspx
Conceptual drawings of the environmental test chamber:
The following is a stress analysis of one of the walls. It's fixed by the corners and a 14psi pressure load is applied to the wall (at room temperature). Results conclude that deflection is minimal, however more materials should be looked into.
Full analysis report: Cylinder: cylinder-simulationxpress_study-1.docx
Bottom Plate: bottom-simulationxpress_study-1.docx