| In satellite laser communication links,Fast Steering Mirror(FSM) is a critical execution device,and mainly composed of piezoelectric ceramic(PZT), Invar flexible hinge,housing, displacement sensors and internal traces composition.It is the use of the reverse piezoelectric effect of piezoelectric ceramic to drive to achieve flexible hinge deflection plane mirror. In the process of pointing, acquisition and tracking, decreasing repeat-ability and slowing response time directly affect the quality of the communication link, thereby affecting the normal PAT system.The driving member-piezoelectric ceramic inside the FSM,electrical characteristics of itself exhibits approximately capacitance characteristics and large capacity.So it is difficult to control for piezoelectric ceramic in higher requirements.Due to restrictions by the level of technology, there will be a number of pores,cracks, or inclusions in piezoelectric ceramic.In monotonous or alternating action, the formation of fatigue damage,leading to their capacitance characteristics change, further cause device failure.Therefor-e, it has a great significance to carry out an analysis of fatigue damage for the design of piezoelectric ceramic reliability and the prediction of its lifetime. Additionally,flexible hinge movement as the transfer element between piezoelectric ceramic and the plane mirror, its life is also related to the whole fast steering mirror life.Based on the affect of piezoelectric ceramics and flexible hinge for fast steering mirror overall life, this paper first described the effects of FSM working life factors, and by the way of mathematical modeling analyzed the endless flexible hinge life.Therefore,the piezoelectric ceramic was essential to determine the whole working life of FSM;.Secondly,we analyzed the electrical properties of piezoelectric ceramic and hysteresis,and designed piezoceramic electrical test circuit and simulated the reliability of the circuit with simulation software Multism. And with the design of the circuit and written Labview the program tested piezoceramic leakage current, capacitance and hysteresis angle parameters. Finally,we conducted constant stress of high temperature, high pressure and high temperature&high pressure combined effect of accelerated life test to FSM, and obtained a fatigue damage theory of accelerated life model assessment by experimental analysis.And we estimated the working life in different working conditions of FSM with mathematical models. It maked a reference for FSM in orbit applications. |
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