Sirio satellite - Structural-dynamic coupling between launcher and satellite

The general philosophy of the coupled dynamic analysis for the Sirio satellite and its Delta launcher is discussed. An axial-lateral dynamic model of the launcher, obtained by the finite element method, is coupled to the finite element model of the spacecraft. The spacecraft model consists of three reduced substructure stiffness and mass matrices for selected dynamic points and interface attachment points. The forcing functions consist of the lateral lift-off forcing function, the post-pulse responses of which are considered to be accurate in amplitude and frequency content, and axial and lateral sinusoidal forces simulating the Meco-Pogo event. Notching evaluation showed that reduced vibration test levels can be applied at the first lateral resonance of the Sirio satellite during the sinusoidal vibration tests