5. STRUCTURAL ANALYSIS

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Wilfred Merritt
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1 5. STRUCTURAL ANALYSIS The skeletal structure of the experiment casing is constructed from UNISTRUT with all experiment equipment mounted by UNISTRUT provided fasteners. All maximum loads for nuts, bolts, beams, and brackets were obtained from UNISTRUT specifications for each of the respective sizes used in the structure. According to these specifications, all maximum loads include a factor of safety of 2.5 or more. All UNISTRUT specifications for the beams and brackets are located in Table 5.1, while the fasteners (nuts and bolts) are located in Table 5.2. Figure 5.1 below illustrates the structural layout of the apparatus:

2 Missing panel not shown for detail Missing panel with window not shown for detail Floor of chamber not shown for detail 4 floor mounts were placed on the four corners of the experiment

3 Figure 5.1: Structural Design Free body diagrams for all required g-load conditions along with calculations of reaction forces in the mounts are provided in Appendix C. Based on initial calculations of the largest free body diagram, the camera computer unit with a 9g forward loading has the greatest structural load less than 450 lbs. The maximum uniform loading on the UNISTRUT C-beams (A1000) of 36 inches is 475 lbs with a factor of safety of 5. Because the longest beams in the structure are 35 inches in length, there are no structural issues evident from uniform beam loading. The UNISTRUT bracket fittings used in the construction of the experiment skeletal structure all have maximum allowable loads that exceed those of the beams. Because no loads will exceed the largest load of 450 lbs in 9g s on the C-beam, there are no structural issues predicted for any of the brackets. See Appendix D for illustrations of these brackets. Figures D.1 and D.2 illustrate the brackets used for all angles in the frame structure. All the bolts, used to mount the equipment to the skeletal structure and to fasten the structure, are compatible with the NAS Steel Studs supplied by NASA. All UNISTRUT specifications can be viewed at the following website: The specifications are from the General Engineering Catalogue. The overall weight of the structure is 300 lbs completely assembled. Therefore, the maximum load on the structure in a 9g environment is approximately 2700 lbs. There will be a total of four steel bolts that will mount the test apparatus to the aircraft floor, and the bolts supplied (NAS Steel Studs) were more than adequate to support the fraction of the load that was applied to each mount. Table 5.1: Component Weights Component Material Size Allowable Tensile Shear Qty Weight Total

4 (in) Moment (in/lbs) Strength Strength / ea Weight FRAME Unistrut Beam Low Carbon 1.25x1.25x Unistrut Beam Low Carbon 1.25x1.25x Unistrut beam Low Carbon 1.25x1.25x Unistrut Beam Low Carbon 1.25x1.25x Unistrut Fittings 2.94x3.90x3.90 Designed to take more force and moment than the Unistrut beams Aluminum Plate Aluminum 0.125x25x25 N/A 1270 N/A Aluminum Plate Aluminum 0.125x35x25 N/A 1270 N/A Aluminum Plate Aluminum 0.125x35x35 N/A 1270 N/A Aluminum Plate Aluminum 0.125x60x25 N/A 1270 N/A EXPERIMENT COMPONENTS Camera Steel/Plastic/Al 3.34x3.34x7.48 N/A N/A N/A Camera Shelf Steel/Aluminum 9.5x8x0.25 N/A 300 N/A Camera Steel/Plastic 16.93x8.66x19.68 N/A N/A N/A Controller CPU Straps Aluminum 25x2x0.125 N/A 500 N/A CPU Brackets Steel 4x2x0.125 N/A 3000 N/A Amp Plastic 5.125x16.56x12.25 N/A N/A N/A Amp Straps Al 15x2x0.125 N/A 500 N/A Amp Brackets Steel 4x2x0.125 N/A 3000 N/A Laptop Plastic 12.6x10x1.5 N/A N/A N/A 1 6 6

5 Gas Cylinders Stainless Steel OD 2, L 8.94 N/A N/A N/A Cylinder Bracket Aluminum 1x3.5x7 N/A N/A N/A Gas Plumbing Steel OD.25, L 35 N/A N/A N/A Unistrut Steel 1.25x.3x1.25 N/A N/A N/A Plumbing Bracket PFA Al OD 2,L 4 N/A N/A N/A Table 5.2: Properties of Fasteners Type Size Shear Strength Tensile Strength Unistrut Hex Head Cap Screw 3/8 x 1 1/ Unistrut Flat Head Machine Screw 5/16 x Unistrut Channel Nut 3/ Unistrut Threaded Rod 3/8 N/A 610 Unistrut Hex Nut 3/8 N/A N/A

Foundation Products. Poured In Ground Anchor Bolts E1 - E4. Structural Foundations E5 - E12. Copyright 2016 s Industry Inc. SIE-RA-CMP EN

Foundation Products. Poured In Ground Anchor Bolts E1 - E4. Structural Foundations E5 - E12. Copyright 2016 s Industry Inc. SIE-RA-CMP EN Foundation Products Poured In Ground Anchor Bolts E1 - E4 Structural Foundations E5 - E12 EA EB Poured in Ground Anchor Bolts Layout SIEMENS Anchor Bolts 131702-4X shown for reference purposes only! Actual