Master Thesis - OUFTI-1

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The xEPS card This card is presented in Figure 5.5. Figure 5.5: The xEPS card developed in collaboration with Thales Alenia Space ETCA Except for one (situated at the top of the image, on the left), all the components of this card belong to the SMT category. So, once again, all the components will be modeled using the global mass smearing method. The P C 104 connector will still be modeled using the same method that in the previous cases. The properties nally obtained for this card, are presented in Table 5.5. Components Young's moduli (GP a) Poisson ratios Densities (kg/m 3 ) P C 104 connector 0.846 0.3 1406.923 PCB 20 0.3 3404.345 Table 5.5: Properties of the xEPS card The COM card Unfortunately, at the moment when this thesis ends, this card is not yet manufactured. So, no picture of it can be presented. In addition, no accurate information are available for this card (e.g., concerning its mass). Its nal mass was estimated to maximum 65 g by the COM subsystem. So, like for the other electronic cards, the P C 104 connector will be model accurately and the mass of the other components will be spread out over the entire PCB. The properties nally obtained for this card, are presented in Table 5.6. 107
Components Young's moduli (GP a) Poisson ratios Densities (kg/m 3 ) P C 104 connector 0.846 0.3 1406.923 PCB 20 0.3 4046.952 Table 5.6: Properties of the COM card Battery support The battery support is more dicult to model. Indeed, its two parts (the box and the cover), made of Al − 7075 T 6, have specic geometries which do not allow to model them using shell elements. So, to be as accurate as possible, it was decided to model these two parts using volume elements. For the batteries, the problem is quite dierent. These ones do not have a constant thickness, and their Young's modulus is not known. So, it was decided to represent them using a local mass smearing method (the mass of the batteries can be obtained by weighting them or by consulting their datasheet). As remind, the density of the battery is 2159.25 kg/m 3 . Then, the batteries are xed to their support using a "glue" assembly. Assembly These ve electronic cards and the battery support are all xed on the endless screws. To realize these connections, some vertex were added to each endless screws, at the level of each of these components. These vertex are used to create the endless screws and so, are rigidly xed to them. Then, a "mean" assembly is applied between each vertex and the wire of its corresponding hole on the considered component. 5.2.6 The endless screws The endless screws, due to their higher dimensions and to the fact that they are involved in a lot of connections (as explained in section 5.2.5), will be modeled more accurately than the screws which connect the CSK structural parts together. These screws are M3 × 8 cm stainless steel screws. So, to model them accurately, a circular beam behavior was used, with a diameter of 2.459 mm, which corresponds to the M3 standard. In reality, these screws are connected to the base plate at one extremity, and to the chassis at the other, thanks to the midplane standos. For the rst connection, the same assembly method as the one used for the electronic cards and the battery support, is applied. For the second one, an homemade method was imagined. The midplane standos were replaced by two vertex connected together using a "xed" assembly. To clarify the following explication, Figure 5.6 shows this particular modeling. One of these vertex (1) is 108
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University of Liège Faculty of App
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Abstract OUFTI-1, standing for "Orb
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3.4 Initial idea . . . . . . . . .
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List of Figures 1.1 The Pumpkin's C
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4.18 MAC matrix using the simple me
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List of Acronyms ADCS Al AlNiCo ASI
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Thesis outline This thesis focuses
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of larger satellites. So, the CubeS
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1.2 OUFTI-1 project 1.2.1 Genesis O
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• XatCobeo (Vigo - Spain): Develo
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Chapter 2 OUFTI-1: Flight system co
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Figure 2.2: Product tree of OUFTI-1
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2.3.2 Solar panels The armor panels
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• We do not want to drill or manu
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In our case, because of the limited
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Figure 2.13: Magnetic eld obtained
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Figure 2.17: Pictures of the ADCS c
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consider the possibility of oshorin
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Figure 2.20: Exploded view of OUFTI
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I xx , I yy and I zz are called the
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Subsystem: Structure & Conguration
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Subsystem: Thermal Control Parts Co
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Chapter 3 Design of a new support f
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Figure 3.3: Batteries during and af
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The concept is the following one: F
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A test under vacuum conditions was
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Thermal Expansion (CTE) of the mate
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Figure 3.9: Classication by density
Page 57 and 58: The last property to determine is t
Page 59 and 60: • So, it was decided to use two t
Page 61 and 62: is to prevent the batteries' bulge.
Page 63 and 64: • Then, the thermostats, that wil
Page 65 and 66: Figure 3.23: Schematics of the cove
Page 67 and 68: • Other components, including the
Page 69 and 70: 3.9.3 Dynamic behavior Finally, it
Page 71 and 72: 3.10 Summary Through this chapter,
Page 73 and 74: Chapter 4 Electronic cards dynamic
Page 75 and 76: Figure 4.1: Example of manufacturin
Page 77 and 78: Figure 4.4: Illustration of the exp
Page 79 and 80: Figure 4.5: MAC between the two mod
Page 81 and 82: • Global mass/stiness smearing me
Page 83 and 84: 4.2.6 Modeling of the chassis A gen
Page 85 and 86: Q = ω k = 1 ω b − ω a 2 ζ ⇒
Page 87 and 88: Their study was based on the fact t
Page 89 and 90: Figure 4.14: Example of spacecraft
Page 91 and 92: Figure 4.15: Location of measuremen
Page 93 and 94: Figure 4.18: MAC matrix using the s
Page 95 and 96: 4.3.6 Application of the local mass
Page 97 and 98: ρ P C 104 connector = 10.12 × 10
Page 99 and 100: According to this particular shape,
Page 101 and 102: This is due to the fact that this c
Page 103 and 104: environment. Then, this model is ex
Page 105 and 106: 5.2.4 Antenna support For the anten
Page 107: Components Young's moduli (GP a) Po
Page 111 and 112: 5.3 Static analysis As described in
Page 113 and 114: Figure 5.9: Illustration of the com
Page 115 and 116: Figure 5.11: Maximal Von Mises stre
Page 117 and 118: Figure 5.12: First mode of OUFTI-1
Page 119 and 120: Figure 5.15: Precise PSD of Vega [5
Page 121 and 122: Chapter 6 Conclusions This master t
Page 123 and 124: provided for each method used. We h
Page 125 and 126: last versions of the Verication Con
Page 127 and 128: [13] Ph. LEDENT. "Design and Implem
Page 129 and 130: [40] "Dejond - Aluminum Catalog ".
Page 131 and 132: Appendix A Schemas of solar panels
Page 133 and 134: Appendix B Schemas of electronic ca
Page 135 and 136: Appendix C Fixations of the endless
Page 137 and 138: Appendix D Datasheet of the battery
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Master Thesis - OUFTI-1

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