Master Thesis - OUFTI-1

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3.6.2 Objective function and CES software Selecting particular materials and manufacturing process is a complex task that needs several iterations to be carried through. The procedure used here is based on references [38] and [39]. The rst step consists in dening one or several objective functions that allow to classify the materials. In our case, the objective is to obtain a reliable support with a minimal weight. So, two objective functions can be dened (see Equations 3.6.1 and 3.6.2). M 1 = E1/2 ρ (3.6.1) M 2 = σ2/3 y (3.6.2) ρ where M 1 and M 2 are the performance index to maximize, E is the Young's modulus of the material, ρ is its density and σ y is its yield stress. According to these functions, it is possible to use the CES software to realize the material selection. This powerful software, developed by the Prof. M. ASHBY, includes a complete material database coupled with a program that classies material with regard to predined properties. In our case, the four materials listed in section 3.6.1 were classied using the CES software. The graphs obtained are presented in Figures 3.8 and 3.9. Figure 3.8: Classication by density and Young's modulus 53
Figure 3.9: Classication by density and yield stress So, the nal classication of these materials is: 1. CFRP 2. Al alloys 3. GFRP 4. T i alloys However, an other important criterion to take into account is the cost. Indeed, each of these materials has a given cost, which is not the same for each of them. Moreover, the cost is also closely linked to the manufacturing process which can be used to modeled the material into the desired form. For this reason, Al alloys become more attractive than CFRP. In addition, the choice of Al alloys allows to create a support with more restricted dimensions, which is really important considering the available space between EPS and xEPS cards. The selection of a particular alloy was then based on an ESA requirement which stipulates that: "Aluminum 7075 or 6061 shall be used for both the main CubeSat structure and the rails. If other materials are used the developer shall submit a Deviation Waiver Approval Request (DAR) and adhere to the waiver process ". In this requirement, the denition for a "CubeSat main structure" is the following one: a main structure is a structure which supports, in addition to its own weight, the weight 54
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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 and 52: A test under vacuum conditions was
Page 53: Thermal Expansion (CTE) of the mate
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
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5.2.4 Antenna support For the anten
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Components Young's moduli (GP a) Po
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Components Young's moduli (GP a) Po
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5.3 Static analysis As described in
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Figure 5.9: Illustration of the com
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Figure 5.11: Maximal Von Mises stre
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Figure 5.12: First mode of OUFTI-1
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Figure 5.15: Precise PSD of Vega [5
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Chapter 6 Conclusions This master t
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provided for each method used. We h
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last versions of the Verication Con
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[13] Ph. LEDENT. "Design and Implem
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[40] "Dejond - Aluminum Catalog ".
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Appendix A Schemas of solar panels
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Appendix B Schemas of electronic ca
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Appendix C Fixations of the endless
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Appendix D Datasheet of the battery
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Master Thesis - OUFTI-1

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