Aerospace Technic and Technology

The dynamic processes in the rocket fairing when the pyrotechnic separation system is triggered are considered. The fairing construction is mixed and includes composite and metal elements. The main composite construction element is a fiberglass shell with regular and irregular winding zones. The speed acceleration required to separate the fairing occurs under the action of impulse pressure from the powder gases in the pyrotechnic system. The displacement of the fairing is made up of displacements of the movement as a rigid whole along its axis and vibrations caused by deformations. The calculation of the fairing movement is carried out according to a three-dimensional FEM model using software that uses a topologically regular discretization system. The problem solution in time is performed according to the implicit Wilson finite-difference scheme. When studying the fairing dynamics, it is allowed to break the structure of the shell in the form of lamination, which in the FEM scheme is modeled by a special method. A cut with double nodes is created on the surface of the proposed lamination along topological planes by transforming the finite element mesh. Modification of the stiffness matrix and mass matrix for the transformed mesh is performed based on the created information base of degenerate finite elements and formalized matrix operations. In numerical studies, two types of lamination from irregular zones of fiberglass winding are considered – the internal location from the flange and edge location with access to the fairing free edge. The results of calculating vibrations along the sides of lamination and data on the redistribution of dynamic stresses due to lamination are presented. Radial and axial displacements when passing through the lamination surface discontinue, the magnitude of which for internal lamination is much less, which is explained by the compression of deformation for this case, in contrast to the lamination that goes to the boundary. When estimating the relative axial displacements, the component of the displacement of a rigid whole, determined by a separate calculation, was excluded. The maximum radial displacements during lamination from the edge reach 3 mm, which is one and a half times higher than for an undamaged shell. Axial stresses are maximal from the action of inertial forces during acceleration. Its redistribution over the layers is significantly greater for the edge lamination, for which the maximum values increase almost two times concerning the undamaged shell, which determines this type of lamination as more dangerous.

fairing; rocket; composite; lamination; separation; curvilinear anisotropy; impulse loading; dynamic strength

Degtyarev, A. V., Kovalenko, V. A., Potapov, A. M. Primenenie kompozitnykh materialov pri sozdanii perspektivnykh obraztsov raketnoi tekhniki [The use of composite materials in the creation of advanced models of rocket technology]. Aviacijno-kosmicna tehnika i tehnologia – Aerospace technic and technology, 2012, no. 2 (89), pp. 34–38.

Potapov, A. M., Kovalenko, V.A., & Kondrat'ev, A. V. Sravnenie golovnykh obtekatelei sushchestvuyushchikh i perspektivnykh otechestvennykh raket-nositelei i zarubezhnykh analogov [Comparison of head fairings of existing and prospective domestic launch vehicles and foreign analogues]. Aviacijno-kosmicna tehnika i tehnologia – Aerospace technic and technology, 2015, no. 1 (118), pp. 35–43.

Gaidachuk, A. V. (Ed.), Gaidachuk, V. E., Kondrat'ev, A. V., Kovalenko, V. A., Kirichenko, V. V., & Potapov, A. M. Metodologiya razrabotki effektivnykh konstruktivno-tekhnologicheskikh reshenii kompozitnykh agregatov raketno-kosmicheskoi tekhniki [Methodology for the development of effective structural and technological solutions for composite aggregates of rocket and space technology] in 2 vols. Vol. 1. Sintez parametrov kompozitnykh agregatov raketno-kosmicheskoi tekhniki pri raznorodnom nagruzhenii [Synthesis of parameters of composite aggregates of rocket and space technology under dissimilar loading]. Kharkov, National Aerospace University "KhAI" Publ., 2016. 250 p.

Kondrat'ev, A. V., Kovalenko, V. A. Optimiza-tsiya proektnykh parametrov kompozitnogo golovnogo obtekatelya rakety-nositelya pri odnovremennom silovom i teplovom nagruzhenii [Optimization of design parameters of a composite nose fairing of a launch vehicle with simultaneous power and thermal loading]. Kosmichna nauka i tekhnolohiia – Space Science and Technology, 2019, vol. 25, no. 4, pp. 3–21. DOI: 10.15407/knit2019.04.003.

Kulaga, E. S., & Olenin, I. G. Razrabotka golovnykh obtekatelei iz kompozitsionnykh materialov [Development of composite head fairings]. Vozdushnyi transport – Air Transport, 2006, iss. 1, pp. 418–436.

Peigano, N. Mezhsloinye effekty v kompozitnykh materialakh [Interlayer effects in composite materials]. Moscow, Mir Publ., 1993. 346 p.

Grishchenko, S. V. Raschet i proektirovanie izdelii konstruktsii samoleta iz sloistykh kompozitov s uchetom mezhsloevykh effektov [Calculation and design of aircraft construction products from layered composites taking into account interlayer effects]. Trudy MAI, 2015, iss. 84, pp. 1–19.

Shulzhenko, N. G., Gontarovskiy, P. P., & Zaytsev, B. F. Zadachi termoprochnosti, vibrodiagnostiki i resursa energoagregatov (modeli, metody, rezultaty issledovaniy): monografiya [Problems of thermal strength, vibration diagnostics and resource of energy-generating units (models, methods, research results) : monograph]. Saarbrücken, Germany: LAP LAMBERT Academic Publishing GmbH & Co.KG, 2011. 370 p.

Asaenok, A. V., Zaitsev, B. F., Shul'zhen-ko, N. G. Metodika vvedeniya razrezov v skheme metoda konechnykh elementov v zadachakh statiki i sobstvennykh kolebanii trekhmernykh konstruktsii [Technique for introducing cuts in the finite element method scheme in problems of statics and natural vibrations of three-dimensional structures]. Problemy mashinostroeniya – Journal of Mechanical Engineering, 2003, vol. 6, no. 3, pp. 58–63.

Bathe, K-J. Finite Element Procedures. Prentice Hall, 1996. 1037 p.

Zaitsev, B. F., Asaenok, A. V., Protasova, T. V., Klimenko, D. V., Akimov, D. V., & Sirenko, V. N. Dinamicheskoe napryazhenno-deformirovannoe sosto-yanie kompozitnogo obtekatelya pri otdelenii ot rakety [Dynamic stressed-deformed state of a composite dome when separating from a rocket]. Vestnik dvigatelestroeniya – Herald of Aeroenginebuilding, 2018, no. 2/2018, pp. 129–135.

Zaitsev, B. F., Shul'zhenko, N. G., & Asaenok, A. V. Metod rascheta kolebanii tel, soderzhashchikh treshchiny s kontaktiruyushchimi beregami [Method for calculating vibrations of bodies containing cracks with contacting edges]. Problemy mashinostroeniya – Journal of Mechanical Engineering, 2008, vol. 11, no. 4, pp. 34–42.