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MKIR Vacuum Jacket FEA. Model, Results, and Recommendations. Overall FEM Summary. Used finite element model (FEM) generated for previous analysis of the entire experiment 133,600 nodes 65,700 elements (parabolic formulation) All critical components explicitly modeled where possible
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MKIR Vacuum Jacket FEA Model, Results, and Recommendations
Overall FEM Summary • Used finite element model (FEM) generated for previous analysis of the entire experiment • 133,600 nodes • 65,700 elements (parabolic formulation) • All critical components explicitly modeled where possible • Some components represented using lumped masses and rigid elements
Boundary Conditions • Model is grounded at top of ISS/VJ Interface • One standard atmosphere of pressure (14.7 psi) was applied to the Vacuum Jacket • Conservative since experiment should be at altitude • Results scale linearly with pressure • Top of Mauna Kea (~13,000 ft) atm = ~8.8 psi • Scale all results by .6
Stresses Due to Pressure • Highest stresses due to pressure load are found in the vacuum jacket covers • Red channel cover max stress = 10ksi (Von Mises stress) • Blue channel cover max stress =
Red Channel Cover • Maximum stress in gusset and near edge • 10.0 ksi
Blue Channel Cover • Maximum stress in gusset and near edge • 8.8 ksi
Conclusions • Pressure load case shows positive margins • Assumes Aluminum 6061-T6 • Yield allowable of 35 ksi • Maximum stress of 10.0 ksi in red channel cover • Margin of safety of 2.5 • Margin improves for higher altitude installation • Displacements calculated and reported in separate spreadsheet