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Abstract

Employing the finite element and computational fluid dynamics methods, we have determined the conditions for the fragmentation of space bodies or preservation of their integrity when they penetrate into the Earth's atmosphere. The origin of forces contributing to the fragmentation of space iron bodies during the passage through the dense layers of the planetary atmosphere has been studied. It was shown that the irregular shape of the surface can produce transverse aerodynamic forces capable of causing deformation stress in the body exceeding the tensile strength threshold of iron.

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  • V V Adushkin
  • I V Nemchinov
Adushkin V. V., Nemchinov I. V., 1994, Space Science Series. University of Arizona Press, Tucson, p. 721
  • B Baldwin
  • Y Sheaffer
Baldwin B., Sheaffer Y., 1971, J. Geophys. Res., 76, 4653
  • Y I Fadeenko
Fadeenko Y. I., 1997, Combust. Explosion Shock Waves, 3, 172
  • B Giese
  • G Neukum
  • T Roatsch
  • T Denk
  • C Porco
Giese B., Neukum G., Roatsch T., Denk T., Porco C., 2006, Planet. Space Sci., 54, 1156
  • S S Grigoryan
Grigoryan S. S., 1979, Kosm. Issled., 17, 875
The Physics and Astronomy of Meteors, Comets, and Meteorites. McGraw-Hill Series in Undergraduate Astronomy
  • G S Hawkins
Hawkins G. S., 1964, The Physics and Astronomy of Meteors, Comets, and Meteorites. McGraw-Hill Series in Undergraduate Astronomy. McGraw-Hill, New York Hills J. H., Goda M.P., 1993, AJ, 105, 1114
Fundamentals of Finite Element Analysis. McGraw Hill Education 1993, Manual of the ICAO Standard Atmosphere, Doc 7488-CD. International Civil Aviation Organization
  • D Hutton
Hutton D., 2017, Fundamentals of Finite Element Analysis. McGraw Hill Education 1993, Manual of the ICAO Standard Atmosphere, Doc 7488-CD. International Civil Aviation Organization, Montreal, Quebec
  • A G Ivanov
  • V A Ryzhanskii
Ivanov A. G., Ryzhanskii V. A., 1999b, Combust. Explosion Shock Waves, 35, 581
Theory of Elasticity, 4 edn
  • L D Landau
  • E M Lifshitz
Landau L. D., Lifshitz E. M., 1980, Theory of Elasticity, 4 edn. Course of Theoretical Physics Vol. 7. Butterworth-Heinemann, Oxford
Dynamics and Thermodynamics of Planetary Entry
  • W H T Loh
Loh W. H. T., 1963, Dynamics and Thermodynamics of Planetary Entry. Prentice-Hall, NJ
Atmospheric Entry -An Introduction to Its Science and Engineering
  • J J Martin
Martin J. J., 1966, Atmospheric Entry -An Introduction to Its Science and Engineering. Prentice-Hall, NJ
Hazards Due to Comets and Asteroids
  • D Morrison
  • C R Chapman
  • P Slovic
Morrison D., Chapman C. R., Slovic P., 1994, Hazards Due to Comets and Asteroids. University of Arizona Press, Tucson, p. 59
  • S P Naidu
Naidu S. P., et al., 2015, AJ, 150, 54
Handbook of Resistance to Materials
  • G Pisarenko
  • A Yakovlev
  • V Matveev
Pisarenko G., Yakovlev A., Matveev V., 1975, Handbook of Resistance to Materials. Naukova Dumka, Kiev
Aerodynamics of Bolides
  • V P Stulov
  • V N Mirskiy
  • A I Vyslyi
Stulov V. P., Mirskiy V. N., Vyslyi A. I., 1995, Aerodynamics of Bolides. Moscow, Nauka
Lunar and Planetary Science Conference. XXIV. Lunar and Planetary Institute
  • A V Teterev
  • I V Nemchinov
Teterev A. V., Nemchinov I. V., 1993, Lunar and Planetary Science Conference. XXIV. Lunar and Planetary Institute, Houston, p. 1415
Manual of the ICAO Standard Atmosphere, Doc 7488-CD. International Civil Aviation Organization
  • D Hutton
Hutton D., 2017, Fundamentals of Finite Element Analysis. Tata McGraw Hill, India ICAO, 1993, Manual of the ICAO Standard Atmosphere, Doc 7488-CD. International Civil Aviation Organization, Montreal, Quebec Ivanov A. G., Ryzhanskii V. A., 1999a, Combust. Explosion Shock Waves, 35, 326
  • A G Ivanov
  • V A Ryzhanskii
Ivanov A. G., Ryzhanskii V. A., 2005, Combust. Explosion Shock Waves, 41, 346
Proceedings of XIX All-Russian Seminar 'Modelling of Non-Equilibrium Systems (MNS-2016)
  • D E Khrennikov
  • A K Titov
  • A E Ershov
  • S V Karpov
Khrennikov D. E., Titov A. K., Ershov A. E., Karpov S. V., 2016, Proceedings of XIX All-Russian Seminar 'Modelling of Non-Equilibrium Systems (MNS-2016)'. Institute of Computational Modelling Press, Krasnoyarsk, p. 123
  • V P Stulov
Stulov V. P., 1998, Astronom. Vestn., 32, 455