# Small Satellite

 This tutorial is also available for Matlab in: echodemo TutorialSmallSatellite

 Tutorial for the graphical user interface File -> New -> Tutorial -> Tutorial 11. Small Satellite (see also Import Tutorial)

In this tutorial, a small satellite structure will be presented.

## Description of the deterministic FE model

The FE model contains approximately 900 QUAD4 elements ( ~5300 DOF’s). All DOF’s of the nodes at the bottom of the nozzle have been constrained modelling the boundary conditions that the nozzle is attached to the supporting structure with bolts and a vertical acceleration of 6g has been applied together with a horizontal acceleration of 1g (g = 9.81m/s2). Linear static analysis has been performed with MSC.Nastran.

## Definition of the probabilistic model

The structure consists of 4 components, namely nozzle, upper and lower panels, central cylinder and the vertical panels. Depending on the considered cases, various probabilistic models can be created for this structure. For the current tutorial, the uncertainties in Young's modulus, density and thickness will taken into account for each component:

 Summary of the Probabilistic Model Structural Property Distribution Mean Value CoV Value Young's Modulus x 4 Normal (truncated) 70 GPa 0.15 Density x 4 Normal (truncated) 2700 kg/m3 0.10 Thickness x 4 Normal (truncated) 0.15 cm 0.05 Total no of random parameters 12

The corresponding identifiers of the above defined probabilistic model should appear as follows within the NASTRAN input file: (property and material cards 1-6 correspond to the vertical panels, 7 to the cylinder, 8-9 to the upper and lower panels and 10 to the nozzle)

```MAT1 ,1 ,  <cossan name="Evert"   format="%10.4e" original="1" />  , ,  0.3  , <cossan name="Dvert"   format="%10.4e" original="1" />
MAT1 ,2 ,  <cossan name="Evert"   format="%10.4e" original="1" />  , ,  0.3  , <cossan name="Dvert"   format="%10.4e" original="1" />
MAT1 ,3 ,  <cossan name="Evert"   format="%10.4e" original="1" />  , ,  0.3  , <cossan name="Dvert"   format="%10.4e" original="1" />
MAT1 ,4 ,  <cossan name="Evert"   format="%10.4e" original="1" />  , ,  0.3  , <cossan name="Dvert"   format="%10.4e" original="1" />
MAT1 ,5 ,  <cossan name="Evert"   format="%10.4e" original="1" />  , ,  0.3  , <cossan name="Dvert"   format="%10.4e" original="1" />
MAT1 ,6 ,  <cossan name="Evert"   format="%10.4e" original="1" />  , ,  0.3  , <cossan name="Dvert"   format="%10.4e" original="1" />
MAT1 ,7 ,  <cossan name="Ecyl"    format="%10.4e" original="1" />  , ,  0.3  , <cossan name="Dcyl"    format="%10.4e" original="1" />
MAT1 ,8 ,  <cossan name="Ehor"    format="%10.4e" original="1" />  , ,  0.3  , <cossan name="Dhor"    format="%10.4e" original="1" />
MAT1 ,9 ,  <cossan name="Ehor"    format="%10.4e" original="1" />  , ,  0.3  , <cossan name="Dhor"    format="%10.4e" original="1" />
MAT1 ,10 , <cossan name="Enozzle" format="%10.4e" original="1" />  , ,  0.3  , <cossan name="Dnozzle" format="%10.4e" original="1" />

PSHELL,    1,  1,   <cossan name="tvert"   format="%10.4e" original="1" />  ,   1, ,   1
PSHELL,    2,  2,   <cossan name="tvert"   format="%10.4e" original="1" />  ,   2, ,   2
PSHELL,    3,  3,   <cossan name="tvert"   format="%10.4e" original="1" />  ,   3, ,   3
PSHELL,    4,  4,   <cossan name="tvert"   format="%10.4e" original="1" />  ,   4, ,   4
PSHELL,    5,  5,   <cossan name="tvert"   format="%10.4e" original="1" />  ,   5, ,   5
PSHELL,    6,  6,   <cossan name="tvert"   format="%10.4e" original="1" />  ,   6, ,   6
PSHELL,    7,  7,   <cossan name="tcyl"    format="%10.4e" original="1" />  ,   7, ,   7
PSHELL,    8,  8,   <cossan name="thor"    format="%10.4e" original="1" />  ,   8, ,   8
PSHELL,    9,  9,   <cossan name="thor"    format="%10.4e" original="1" />  ,   9, ,   9
PSHELL,    10, 10,  <cossan name="tnozzle" format="%10.4e" original="1" />  ,   10, , 10
```