Static And Dynamic Mechanical Properties Analysis Of Laser Communication Ground Terminal System And Its Key Components

Computational physics provides an important tool in solving the problems of complex physical phenomenon in applications. A large number of computation and simulation demand in the study of physics made the rapid development of computational physics. It has a wide range of applications in the various related disciplines of physics and technology.Laser communication ground optical terminal is used as the ground transmitting terminal and receiving terminal of the laser communication, which is responsible for receiving the downlink optical signal and transmitting uplink optical signal. In order to ensure the stability and reliability of the Sateline-to-Ground laser communication, ground optical terminal requires excellent optical and mechanical properties. So in the pre-design stage, in order to achieve the target of optical axis stability,imaging quality, terminal system static and dynamic characteristics, it is of great significance to analyze the static and dynamic mechanical properties of the ground optical terminal system and its key components by means of finite element method.As one of the key components of optical terminal system, the surface precision of primary mirror has important influence on the imaging quality of the whole optical terminal system. We have optimized the design of the distribution of 6 points lateral support and 18 points underside support. The optimization target is to minimize RMS and PV of the mirror surface. The parameters involved in the optimization include radius of inner and outer circle of bottom support and the support angle of lateral support. The results indicated that when the supporting position takes the optimal value, the quality of the primary mirror surface has been greatly improved.In order to guarantee the accuracy of the optical axis of the optical terminal, the gravity deformation of the system has been studied under the working conditions of optical axis zenith and horizontal point. After calculating the relative displacement and rotation angle of the primary and secondary mirror that caused by the deformation of them under the two conditions, we obtained the optical axis tilt and coke of the main optical components, then we calculated the optical axis pointing angle. The results meet the technical requirements well.In order to improve the torsional rigidity of the secondary mirror structure system, the dynamic stability of the second mirror structure system is analyzed by applying different bias and pre-tightening force. The relationship between the size of the wing, the pre tightening force and the natural frequency of the system is obtained. The conclusion has important guiding significance to the improvement of the first order natural frequency of the second mirror system and the structural optimization design.By carrying out the dynamic analysis of the optical terminal system, we obtained the natural frequencies and mode shapes of the first five orders, which can provide guidance for the optimization design of the optical system.