Master Thesis - OUFTI-1

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
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