A Study on Separation Stability of The Umbilical Plug of A Store

발사체의 배꼽 플러그 분리 안정성 연구

Abstract

When a store is launched, the umbilical plug should be separated from the launcher without any physical interference and fragments. In order to satisfy these conditions, an umbilical plug and an umbilical separating device were designed. The plug is separated from the receptacle of the store while moving along inclined planes by the store thrust and the spring force connected from the launcher to the plug. As a result of the prototype test, the hanger on the store collided with the plug. Several tests were conducted after some actions were taken to prevent the collision. However, not only the same phenomenon was repeated, but also fragmentation occurred. In this study, the non-colliding conditions were analyzed through rigid and flexible multi-body dynamics analysis.

Fig. 1. The umbilical separation structures of analogous systems^[2]

Fig. 2. The components of umbilical assembly

Fig. 3. Normal case and collision case of the umbilical plug separation

Fig. 4. The umbilical plug after the prototype test

Fig. 5. The hanger fairing before and after the prototype test

Fig. 6. The umbilical plugs after the Test 0 ~ Test 3

Fig. 7. Both sides of the wings of the umbilical plug

Fig. 8. Upper side of the inclined face in the umbilical separation device

Fig. 9. Spring positions

Fig. 10. The MBD analysis results with respect to the prototype test

Fig. 11. The z-axis displacements of the umbilical plug according to slop angle, spring position, and spring model

Fig. 13. Contact faces between rail and front/rear hangers

Fig. 14. The MFBD analysis results with respect to the prototype test

Fig. 15. The z-axis displacements of the umbilical plug and rail tip

Fig. 12. Flexible body model of the rail

Table 1. Test specification of the prototype umbilical assembly

Table 2. Three kinds of umbilical plug types

Table 3. Test results by the umbilical plug types

Table 4. Spring specification^[3]

Table 5. The results of Eq (1)

Table 6. Analysis cases

Table 7. Mass of bodies

Table 8. Constraints in the model

Table 9. Base contact parameters

Table 10. Action contact parameters

Table 11. Stiffness of contact