Master Thesis - OUFTI-1

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subsystem, was validated by the EPS team. So, the mass and dimensions of the batteries are now known and a rst guess of how arrange the reinforcers can be realized. 3.6 Material selection An other important step for realizing the design of the support, is the selection of the material that will be used to manufacture it. Indeed, the thickness of the dierent parts that must prevent the batteries' bulge, was determined in relation to the properties of the selected material. 3.6.1 Denition of the requirements Firstly, the requirements imposed to the material must be dened precisely. Structural requirements The rst feature of the battery support is its structural integrity during the launch. Indeed, it will have to support the harsh vibration environment without causing damages to the other components of the satellite. So, the strength is an important property that will ensure the structural integrity of the support. The toughness is also an important property to sustain the stage ignition/separation, fairing jettisoning and POGO eects during launch. Then, the structural requirements can be expressed as: • The material shall be rigid (high Young's modulus). • The material shall have a good resistance in traction/compression. • The material shall have a toughness of at least 25 MP a m 0.5 (which is a value typically used in the space applications). Thermal requirements Firstly, the material shall resist to the operating temperature range of the batteries ([0 ◦ C − 40 ◦ C]). Then, thermal variations inside the CubeSat can disturb the batteries' performances. These variations can be limited by using a material with a high thermal inertia. In addition, the heat produced by the heaters must only serve to maintain the batteries' temperature in an acceptable range. Any waste of energy could cause important problems on the power distribution inside the satellite. So, a material with a low thermal conductivity is preferable to keep the heat inside the support. Finally, thermal cycling can also induce deformations of the support. However, in this case, the support could not play its role of preventing the batteries' bulge. This eect can be limited if the Coecient of 51
Thermal Expansion (CTE) of the material is not too high (e.g, CTE of the CSK structure is: 20 − 25 µstrain/K). Then, the thermal requirements can be expressed as: • The material shall resist to temperature range [−10 ◦ C − 50 ◦ C] (by taking a security margin of 10 ◦ C). • The material shall shield batteries against thermal variations. • The material shall have a low thermal conductivity (however, if this requirement is not respected, it is possible to use some thermal insulators between the batteries and their support). • The material shall have a low CTE. Outgassing requirements These requirements are imposed by the ESA [37]: • Total Mass Loss (TML) of the material shall be ≤ 1%. • Collected Volatile Condensable Material (CVCM) of the material shall be ≤ 0.1%. Presetting In accordance with all these requirements, four materials were selected: Al alloys, Carbon Fiber Reinforced Plastic (CFRP), GFRP and T i alloys. All of these materials fulll all the requirements and they are all typically used in space applications. Their general properties are available in Table 3.4. Materials Densities (kg/m 3 ) Young's moduli (GP a) Yield stresses (MP a) Al alloys 2500 − 2900 68 − 80 95 − 610 CFRP 1500 − 1600 69 − 150 550 − 1050 GFRP 1750 − 1970 15 − 28 110 − 192 T i alloys 4400 − 4800 110 − 120 750 − 1200 Table 3.4: Materials properties 52
Page 1 and 2: University of Liège Faculty of App
Page 3 and 4: Abstract OUFTI-1, standing for "Orb
Page 5 and 6: 3.4 Initial idea . . . . . . . . .
Page 7 and 8: List of Figures 1.1 The Pumpkin's C
Page 9 and 10: 4.18 MAC matrix using the simple me
Page 11 and 12: List of Acronyms ADCS Al AlNiCo ASI
Page 13 and 14: Thesis outline This thesis focuses
Page 15 and 16: of larger satellites. So, the CubeS
Page 17 and 18: 1.2 OUFTI-1 project 1.2.1 Genesis O
Page 19 and 20: • XatCobeo (Vigo - Spain): Develo
Page 21 and 22: Chapter 2 OUFTI-1: Flight system co
Page 23 and 24: Figure 2.2: Product tree of OUFTI-1
Page 25 and 26: 2.3.2 Solar panels The armor panels
Page 27 and 28: • We do not want to drill or manu
Page 29 and 30: In our case, because of the limited
Page 31 and 32: Figure 2.13: Magnetic eld obtained
Page 33 and 34: Figure 2.17: Pictures of the ADCS c
Page 35 and 36: consider the possibility of oshorin
Page 37 and 38: Figure 2.20: Exploded view of OUFTI
Page 39 and 40: I xx , I yy and I zz are called the
Page 41 and 42: Subsystem: Structure & Conguration
Page 43 and 44: Subsystem: Thermal Control Parts Co
Page 45 and 46: Chapter 3 Design of a new support f
Page 47 and 48: Figure 3.3: Batteries during and af
Page 49 and 50: The concept is the following one: F
Page 51: A test under vacuum conditions was
Page 55 and 56: 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 and 108:
Components Young's moduli (GP a) Po
Page 109 and 110:
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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