Research On The Design Method Of Shock Reduction And Performance Analysis For A Typical Separation Nut

Separation nut is a kind of typical pyrotechnic point-separation device. It has advantages for no-pollution, easy to install and lower pressure required for release. So it is well suited for stage separation, payload separation and so on. Type and quantity of precision instruments applied to launch vehicles are much more with the rapid development of our space engineering in recent years. These high precise instruments are sensitive to shock environment and the requirement for low shock environment is more urgent. The additional shock and impulse induced by separation actions of these devices during the separation pro cess of multi-stage rocket must decrease to an acceptable level. Then it can effectively increase the service life and operational reliability of these precise instruments. So it is of great strategic importance to the development of the overall technology of spacecraft. In order to further decrease the shock of separation nut, the shock source of a pyrotechnic separation nut is analyzed based on its fundamental structure and working principle combined with actual engineering applications. Then the major shock source of the device is determined. For this kind of shock source, a design solution is put forward for mitigating the shock output of the device. Then the test and simulation of the design solution are carried out and the results of the collected data of the two methods are compared. The results show the feasibility of this design solution. And we also obtained the effect of different materials on separation shock. The major research methods and contents have been finished in this paper as follow.(1) A design solution of mitigating its shock output is put forward for a pyrotechnic separation nut. The comparison of different design solutions and materials are finished by contrastive analysis and a kind of cushioning material with superior performance is obtained.(2) The macroscopical deformation process of an aluminum honeycomb under quasi-static load and dynamic compression load is obtained by experiments, respectively. From these results, we can conclude that it is feasible that aluminum honeycomb is applied to the structure of separation nut. Then we obtain the key design points of structure parameter of this material and verify the validation thatusing aluminum honeycomb can remarkably reduce the shock output of this pyrotechnic separation nut on all frequency domains.(3) We also obtain the mechanical parameters of aluminum honeycomb by simulation. The contribution and the effect of aluminum honeycomb with different strength on the shock reduction are studied. The results from simulations are compared with those from experiments and the differences are also analyzed and verified. The motion of each components is quantitatively in agreement with the experimental results while the shock spectrum is qualitatively in agreement with the experimental results.