Dynamic analysis of the plastically deformable spacecraft lander leg

Аuthors

Shcheglov G. A.^*, Lukovkin R. O.^**

Bauman Moscow State Technical University, MSTU, 5, bldg. 1, 2-nd Baumanskaya str., Moscow, 105005, Russia

*e-mail: georg@energomen.ru
**e-mail: LukovkinRO@ya.ru

Abstract

It is proposed to use crash-boxes instead of traditional honeycomb elements in the spacecraft landing shock-absorbing device. The developed design- parameter selection procedure provides a safe spacecraft landing process.
The spacecraft is considered as a point mass equipped with a single support contacting the ground. The formulated problem of non-stationary dynamics is solved using the finite element method, the explicit integration procedure, and the combined MSC.Dytran- MSC.Patran software.
It is assumed, that this single support may include one or more branches of energy-absorbers. Each branch is a group of crash-boxes connected in series by support rings. Axes of the same-branch crash-boxes are aligned. There are three structural schemes of the considered landing device: 1) the single-branch device, 2) the device made of two parallel branches, 3) the device made of two non-parallel branches.
Kinematic and dynamic transients of the specified structural schemes are integrated till the spacecraft point- mass unit overload is obtained. The simulation time- dependent curves characterize the spacecraft landing velocity and acceleration. It is shown, that the point- pass overload level provided by the crash-boxes is close to the overload level provided by the traditional honeycomb elements. Advantage of the proposed crush-box support is its effective damping the peak shock loads.
It is shown, that non-availability of plastic hinges in the absorbing device is the necessary condition of stability of the spacecraft landing process. Longitudinal shock conditions are the most favorable ones for effective shock-absorbing by a separate crush-box. The proposed new non-parallel structural scheme provides the specified longitudinal-shock landing mode.
The obtained simulation results show, that the yielded crash-boxes can provide up to 40% mass saving of the landing-device. These practices may be used by spacecraft engineers for developing future landing devices of re-entering vehicles and interplanetary space-stations.

Keywords:

spacecraft, lander legs, crash-box, numerical simulation

References

1. Bazhenov V.I., Osin M.I. Posadka kosmicheskikh apparatov na planety (Spacecraft landing on the surface of a planet), Moscow, Mashinostroenie, 1978, 159 p. 
2. Kovtunenko V.M. Proektirovanie spuskaemykh avtomaticheskikh kosmicheskikh apparatov: Opyt razrabotki dialogovykh protsedur (Engineering unmanned landers: Experience developing dialogue procedure), Moscow, Mashinostroenie, 1985, 264 p. 
3.  Bakulin V.N., Borzykh S.V., Voronin V.V. Vestnik Moskovskogo aviatsionnogo instituta, 2011, vol. 18, no. 4, pp. 38-46.
   
4. Shao-chun Wang, Zong-quan Deng, Ming Hu, Hai-bo Gao. Dynamic model building and simulation for mechanical main body of lunar lander, Journal of Central South University of Technology, 2005, vol. 12, no. 3, pp. 329-334.
   
5. Bakulin V.N., Kokushkin V.V., Borzykh S.V., Voronin V.V. Vestnik Moskovskogo aviatsionnogo instituta, 2012, vol. 19, no. 5, pp. 45-50.
   
6. Turner R.D. Patent US6227494 B1, 8.05.2001, available at: http://www.google.com/patents/US6227494.
   
7. Yohei Kushida, Susumu Hara, Masatsugu Otsuki, Yoji Yamada, Tatsuaki Hashimoto, Takashi Kubota. Robust Landing Gear System Based on a Hybrid Momentum Exchange Impact Damper, Journal of Guidance, Control and Dynamics, 2013, vol. 36, no. 3, pp. 776-789. (doi: 10.2514/1.58373).
   
8. Buslaev S.P., Stulov V.A., Grigorev E.I. Kosmicheskie issledovaniya, 1983, vol. 21, no. 4, pp. 540-544.
   
9. Khusainov A.Sh., Kuzmin Yu.A. Passivnaya bezopasnost avtomobilya (Passive car safety), Ulyanovsk, Venets UlSTU, 2011, 89 p. 
10. Chung Kim Yuen S., Nurick G. N. The energy — absorbing characteristics of tubular structures with geometric and material modifications: an overview, Applied Mechanics Review — Transactions of the ASME, march 2008, vol. 61.
    
11. Belingardi G., Obradovic J. Design of the Impact Attenuator for a Formula Student Racing Car: Numerical Simulation of the Impact Crash Test, Journal of the Serbian Society for Computational Mechanics, 2010, vol. 4. no. 1, pp. 52-65.
    
12. Fasanella E.L., Lyle K.H., Pritchard J.I. Simulation of X-38 Landing Scenarios With Landing Gear Failures, NASA/TM-2000-210078 ARL-TR-2144, 2000, 72 p.