Enclose the top of the accumulator, stiffen the external walls, isolate the interior and keep water out during the rain test.
A structural lid fastened with 5/16 bolts through aluminium blocks that hold the lock nuts in place while being fastened, with an internal rubber seal gasket for the rain test and for damping.
No part-specific design process is documented. The EV Structures subsystem design process applies: 1. Take the battery segment geometry from Energy Storage: five segments at 15 lb each. 2. Lay out the tower, then set wall thicknesses from available stock above the rules minimum (floor 3.2 mm, walls 2.3 mm). 3. Validate segment structure by hand using Roark's formulas for a plate under uniform pressure, at 40 g fore/aft and lateral and 20 g vertical. Fore/aft gave sigma_max 5.75 ksi and FoS 2.78; lateral gave 9.17 ksi and FoS 1.75; down gave 0.833 ksi and FoS 19.2. 4. Validate each mount independently for static shear, pull-out and bending, fixed at a 0.25 in weld perimeter, at the 15 kN rules requirement. 5. Run structural equivalency for the load-bearing columns: mounting tabs, side wall and front wall cross sections, with I = A*t^2/12. 6. Waterjet the walls, weld on a jigging table with aluminium cube jigs, mill the mounts and weld them to the side walls.
6061 aluminium, 0.125 in thick, with a rubber gasket.
None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.
Nothing in CrimsonStorage covers these yet.