IV.1.4.2 Boundary conditions

Only two different fixations of the satellite are used in the examples of Chapter IV.2:

• The fixations stored in file “launch.bdf” correspond to the clamping of the four lower corner nodes of the satellite. Practically, this is done by defining an RBE2 corresponding to the launcher interface. The six degrees of freedom of the master node are fixed by an SPC. This fixation can be selected by its number identifier: 701001.
• The fixations stored in file “orbit.bdf” correspond to a fixation of the six rigid modes. This is done by defining the appropriate RBE3 element, with CELAS and SPC. This fixation is particularly adapted to the calculation of thermo-elastic load cases in orbit and is selected by its identifier 702001.