皮卫星及其星箭分离机构的热-结构耦合与间隙设计

Design of clearance fit between pico-satellite and its separation mechanism based on thermal-structure coupling

对皮卫星与星箭分离机构进行了热结构耦合分析,以便合理地设计皮卫星与导轨面间的配合间隙,确保皮卫星安全可靠分离。在充分考虑皮卫星发射过程中卫星、地球、太阳三者几何关系的基础上,计算了皮卫星及其星箭分离机构在卫星发射过程中所吸收的外热流;通过有限元分析求解了卫星发射过程中的温度场和热变形情况。基于上述工作,设计了皮卫星与导轨间的配合间隙。分析结果显示:受冷黑环境和传导热流影响,卫星与导轨背阴面变形较大,但皮卫星外壳和导轨面总体并未发生大的扭曲形变;在600N和300N预紧力作用下,皮卫星与导轨面间的配合间隙最大变化量分别为62.3μm和63μm。根据分析结果合理选择了配合公差。得到的结果表明:皮卫星及其星箭分离机构在高低温试验后能正常分离,在轨星箭分离姿态与仿真结果吻合,实验结果验证了卫星与导轨间配合间隙设计的合理性,可用于指导皮卫星星箭分离机构的结构设计和热控制设计。

The thermal-structure coupling for a pico-satellite and its separation mechanism was analyzed to guide a rational design of the fit clearance value between the satellite and guide rail and to ensure safe and reliable satellite separation.On the basis of the geometry relations of the satellite,the earth,and the sun in the process of launching,the internal and external heat flows absorbed by the pico-satellite and its separation mechanism were analyzed.The temperature field and thermal deformation in satellite launching were obtained by finite element analysis.The clearance fit value between the satellite and guide rail was designed on the basis of above analysis.The analysis results show that the maximum deformation occurs on the shady side because of the cold dark environment and conduction heat,and the pico-satellite shell and its guide rail surface are not distorted and deformed seriously.The amount of maximum deformation is 62.3μm when the preload force is 600N and that is 63μm when the preload force is 300N.Based on above analysis results,the fit clearance was selected.These results demonstrate that the pico-satellite and its separation mechanism can separate normally under the high and low temperature tests.The on-orbit separation attitude is in agreement with simulation results well.All of these verify that the fit clearance between the satellite and its guide rail is reasonable and it can be used in the structural design and thermal control design of pico-satellite separation mechanisms.