Micro-Satellite Structure Fracture Investigation techniques

Mounting accuracy of satellite payload and<br/>ADCS (attitude determination and control subsystem) seats<br/>is one of the requirements to achieve the satellite mission<br/>with satisfactory performance. Deviation of the position of<br/>the mounting seat for Multi-Band-Earth-Imager (MBEI) is<br/>caused by cracks in the plate of the basis unit and bracket<br/>for attachment of MBEI. These cracks were detected during<br/>inspection of the satellite strength mock-up after vibration<br/>testing for air transportation phase. Most probable reason of<br/>the cracking is fatigue damage as strength mock-up<br/>structure was subjected to prolonged vibration loading<br/>during various loading cases. Total vibration duration<br/>during testing is about 56 hours. In order to study the<br/>cracking reasons, finite element modeling of the structural<br/>parts of the basis unit including MBEI bracket and<br/>instrument MBEI is subjected to harmonic response to<br/>simulate vibration loading for the case of air transportation.<br/>Numerical results are compared with the experimental ones,<br/>and mechanical design of the basis-plate unit is modified