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For our first run, we tried a Bulkhead with a upper and lower step thickness of 0.5" each. The results showed that this bulkhead would not yield under 3000lbs:
Then, we reduced the thickness to be 0.25" on each step and found that the bulkhead would yield, particularly around the bolt holes and at the contact point with the Avionics Bay coupler, but that overall displacement would be small (~0.2mm):