Head of department – *Corresponding Member of the NAS of Ukraine*, D.Sc., Professor **Volodymyr P. Poshyvalov**

**Field of research:**

- strength and carrying capacity in extreme operating conditions of nonuniform structures for key industries of technology (rocket-space, oil and gas, energy, etc.) with viscoelastoplastic properties of the material, taking into account damage of a different physical nature;
- reliability and durability of engineering systems;

The research conducted at the department includes:

- simulation of the behavior of thin-walled shell-rod systems in extreme operating conditions, solving nonlinear problems of deformation and critical conditions, taking into account operational and technological damage;
- research of the reliability and durability of complex technical systems and objects of space engineering technology;
- development of effective calculation algorithms, software;
- conducting experiments on models and actual structures.

The most important areas of research include:

- mechanics of contact interaction of shell-and-rod systems under complex thermomechanical loadings, in particular local ones;
- nonlinear deformation, limiting states, and optimization of thin-walled nonuniform structures, taking into account operational and technological defects (geometrical imperfections, discontinuities, openings);
- development of projection-iterative schemes for the implementation of numerical methods (finite differences, finite elements, local variations) in the theory of thin-walled structures and in fracture mechanics in order to reduce computer time;
- analysis and simulation of the effect of damage associated with the impact of aggressive environments on the behavior of nonuniform structures;
- creation of methods to develop norms of strength and reliability of elements of aerospace complexes;
- study of various theoretical and experimental issues of the dynamics and strength of thin-walled structures of objects of aerospace engineering, aviation engineering, power, and construction.
- models of damage accumulation, diagnostics of the state of structural elements based on the use of physical phenomena in materials;
- development of methods for assigning accelerated test regimes to reduce the number and duration of control tests for reliability, and expert methods for assessing the possibility of continuing operation after the end of the warranty period;
- development of ways to increase the durability of structural materials due to the excitation of self-organization processes in them with a combined energy load of fields of different nature and force.

The conducted studies allowed us to solve a number of problematic issues for various industries, to significantly reduce material consumption.

According to the research results, 40 monographs were published, the main ones are:

- Hudramovich V.S. Carrying capacity and durability of structural elements / V. S. Hudramovich, E. S. Pereverzev. – Kiev: Naukova Dumka, 1981. – 284 pp;
- Mossakovsky V.I., Hudramovich V.S., Makeev E.M. Contact Problems in Theory of Shells and Rods (in Russian) – Moscow : Mashinostroenie, 1978. – 248 pp;
- Hudramovich V.S. Stability of Elastoplastic Shells (in Russian). – Kiev : Naukova Dumka, 1987. – 216 pp;
- Hudramovich V.S. Thin-walled elements of mirror antennas / V. S. Hudramovich, I. A. Diskovsky, E. M. Makeev. – Kiev: Naukova Dumka, 1986.- 153 pp;
- Mossakovsky V.I., Hudramovich V.S., Makeev E.M. Contact Interactions between Elements of Shell Structures (in Russian). – Moscow : Mashinostroenie, 1988. – 288 pp;
- Pereverzev Ye.S. Reliability and testing of technical systems (in Russian). Kiev: Nauk. Dumka, 1990 .– 328 pp.
- Hudramovich V.S., Demenkov A.F. Elastic-plastic structures with form imperfections and residual stresses (in Russian) Kiev .: Nauk. Dumka, 1991 .– 174 pp.
- Pereverzev Ye.S. Damage accumulation models in durability problems (in Russian). Kiev: Nauk. Dumka, 1995 .– 354 pp.
- Pereverzev Ye.S., Daniev Yu. F. Testing and reliability of technical systems (in Russian). Dnepropetrovsk: NAS, NSA of Ukraine, Institute of Technical Mechanics, 1999. – 223 pp.
- Hudramovich V.S. Creep theory and its applications to the calculation of elements of thin-walled structures (in Russian). Kiev: Nauk. Dumka, 2005 .– 222 p.
- Daniev Yu. F., Bigus G.A. Technical diagnostics of hazardous industrial facilities (in Russian). Moscow: Nauka, 2010 .– 415 pp.
- Bigus G.A., Daniev Yu. F., Bystrova N.A., Galkin D.I. Diagnostics of technical devices (in Russian). Moscow: Publishing house of N. E. Bauman MSTU, 2014 .– 616 pp.
- Hudramovich V. S. Methods of holographic interferometry in the mechanics of inhomogeneous thin-walled structures: monograph / V. S. Hudramovich, A. P. Dzyuba, Yu. M. Selivanov. – Dnipro: Lira, 2017 .– 288 pp
- Hudramovich V. S. Holographic and acoustically sound design of nonuniform design and materials: monograph / V. S. Hudramovich, V. R. Skalsky, Yu. M. Selіvanov. – Lviv: Prostir-M, 2017 .– 492 pp
- Bigus G.A., Daniev Yu. F., Bystrova N.A., Galkin D.I. Fundamentals of diagnostics of technical devices and structures (in Russian). Moscow: Publishing house of N. E. Bauman MSTU, 2018 .– 445 pp.
- Mathematical and computer modeling of engineering systems: Collective monograph (authors: Grebenyuk S. M., Gristchak V. Z, Hart E. L., Hudramovich V. S., Manko N. L., Onyshkevych V. M., Tkachuk N. A., Zaitsev B. P. at al.) / Ed. V. S. Hudramovich. Riga, Latvia: Baltija Publishing, 2020 .– 164 p.

The main research results are published in more than 600 scientific articles, 2 State Standards, 8 copyright certificates, of which the most important ones are:

- Hudramovich V. S. Plastic deformation and limit states of metal shell structures with initial shape imperfections / V. S. Hudramovich, A. A. Lebedev, V. I. Mossakovsky // Light – weight steel and al-uminium structures / Ed. P. Makelainen. – Amsterdam, New York, Tokyo: Elseiver, 1999. – Р. 257 – 263.;
- Нudramovych V. S. Plastic and creep instability of shells with initial imperfections / V. S. Hudramovych// Solid mechanics and its imperfections / ed. G.M.L. Gladwell. – Dordrecht, Boston, London: Kluwer Аcad. Рublishers, 1997. – V. 64. – P. 277 – 289.;
- Hudramovich V.S., Gaiduchenko A.P., Kovalenko A.I. Manufacturing technologies for antenna-waveguide technology and solar energy, based on the method of electrolytic molding (in Russian) // Cosmic science and technology. 2001. T. 7, No. 2/3. – Pp. 66-77.
- Hudramovich V. S. Features of nonlinear deformation and critical states of shell systems with geo-metrical imperfections / V. S. Hudramovich// Int. Appl. Mech. – 2006. – V. 42, No. 12. – Р. 1323 – 1355.;
- Hudramovich V. S. Contact mechanics of shell structures under local loading / V. S. Hudramovich // Int. Appl. Mech. – 2009. – V. 45, № 7. – P. 708 – 729.;
- Hudramovich V.S. Problems of dynamics and strength of constructions of solar energy concentrators (in Russian) // Mater. int. scientific. conf. “Problems of using alternative energy sources in Turkmenistan”. Ashgabat, “Ylym”. – Pp. 46-49.
- Hudramovich V. S. Elastoplastic deformation of nonhomogeneous plates / V. S. Hudramovich, E. L. Hart, S. A. Ryabokon’ // Journ. Engineering Mathematics. – 2013. – V. 78, Issue 1. – P. 181 – 197.;
- Hudramovych V. S. Mutual influence of openings on strength of shell-type structures under plastic deformation / V. S. Hudramovych, E. L. Hart, D. V. Klimenko, S. A. Ryabokon’ // Strength of Materials. – 2013. – V. 45, No. 1. – P. 1 – 9.;
- Poshivalov V.P., Borshchevskaya D.G., Ryabchiy V.D., Telegina I.I. Increasing the durability of the alloy AMg6M due to energy treatment in creep (in Russian) // Physico-chemical mechanics of materials. 2013. #6. – P. 62 – 67.
- Hudramovych V. S. Modeling of the deformation process of concrete based on a modified version of the theory of flow / V. S. Hudramovych, V. M. Levin, E. V. Samarskaja, S. V. Shabelnik // Strength of Materials. – 2014. – V. 46, Issue 5. – P. 595 – 600.;
- Hart E. L., Hudramovich V. S. Projection-iterative schemes for the realization of the finite element method in problems of deformation of plates with holes and inclusions // Journ. of Mathematical Sci. 2014. V. 203, No. 1. – P. 55 – 69.
- Hart E. L.Projection-iterative modification of the method of local variations for problems with a quadratic functional / E. L. Hart, V. S. Hudramovych // Journ. Appl. Math.and Mechanics. – 2016. – V. 80, Issue 2. – P. 156 – 163.;
- Hudramovich V. S. Modeling of the behavior of plane-deformable elastic media with elongated el-liptic and rectangular inclusions / V. S. Hudramovich, E. L. Hart, K. A. Strunin// Materials Science. – 2017. – V. 52, No. 6. – P. 768 – 774.
- Hudramovich V. S., Reprintsev A. V., Ryabokon S. A., Samarskaya E. V. Estimation of the resource of structures of rocket and space technology taking into account the influence of stress concentrators in the form of holes (in Russian) // Technical diagnostics and non-destructive testing. 2016.No. 2. – P. 28 – 36.
- Doyar І., Poshyvalov V. Development of a stochastic model of failure of structural materials in creep at hardening stage // Eastern-European Journ. of Enterprise Technologies. 2016. Vol. 3, no. 5 (81). – P. 25 – 31.
- Degtyarev A. V., Pylypenko O. V, Gudramovich V. S., Daniev Yu. F. et al. On the classification of launch equipment for rocket and space complexes when justifying strength standards (in Russian) // Space Science and Technology. 2016.Vol. 22.No. 1. – Pp. 3-14.
- Hudramovich V.S., Klimenko D.V., Garth E.L. Influence of cutouts on the strength of cylindrical compartments of launch vehicles with inelastic deformation of the material (in Russian) // Cosmic Science and Technology. 2017.Vol. 23, No. 6. – Pp. 12 – 20.
- Hart E. L., Hudramovich V. S. Application of the projection-iterative scheme of the method of local variations to solving stability problems for thin-walled shell structures under localized actions // Strength of Materials. 2018. V. 50, Iss. 6. – P. 852 – 858.
- Hudramovich V. S., Sirenko V. N., Daniev Yu. F., Klimenko D. V., Hart E. L. Development of the normative framework methodology for justifying the residual resource of starting buildings constructions of space launch vehicles // Strength of Materials. 2019. V. 51, No. 3. – P. 333 – 340.
- Hudramovich V. S., Hart E. L., Marchenko О. А. Reinforcing inclusion effect on the stress concentration within the spherical shell having an elliptical opening under uniform internal pressure // Strength of Materials. 2020. Vol. 52, No. 6. – P. 832 – 842.
- Hart E. L., Hudramovich V. S. Projection-iterative schemes for the implementation of variation-grid methods in the problems of elastoplastic deformation of inhomogeneous thin-walled structures // Journ. of Mathematical Sci.. 2021. Vol. 254, No. 1. – P. 21 – 38.
- Gart E.L., Gudramovich V.S. On the application of projection-iterative modifications of variational-grid methods to solving elastoplastic problems in the mechanics of structurally inhomogeneous systems (in Russian) // Elasticity and Inelasticity. Mater. int. scientific. symposium on the problem of the mechanics of deformable bodies, dedicated to the 110th birthday anniversary. A. A. Ilyushin. Moscow: Ed. Moscow State University I. V. Lomonosov, 2021. 158 – 166.

The figures show some of the experimental facilities developed in the department, and shell systems tested in the department’s static testing laboratory, simulating real structures of various branches of engineering (see monographs [3, 5, 7, 10], articles [3, 6, 9]).

Over many years, the department has had scientific relations with the institutes of the National Academy of Sciences of Ukraine: Institute of Mechanics named after S. P. Timoshenko, the Institute of Strength Problems named after G. S. Pisarenko, the Institute of Materials Science named after I. M. Frantsevich, the Institute of Applied Problems of Mechanics and Mathematics named after Ya. S. Podstrigach, with the Yuzhnoe State Design Office named after M.K. Yangel, UkrNDIproektstalkonstruktsii, Kiev National Technical University named after I. Sikorsky, Kiev Polytechnic Institute, the Institute of Mechanics Problems of the Russian Academy of Sciences; the Wroclaw Polytechnic University (Poland); the Academy of Sciences of Turkmenistan; Institute of Mechanics, Moscow State University, Peking University and Harbin University of Technology (People’s Republic of China), etc.

Since 1997, the department has been involved in the implementation of projects under three international contracts with the Ukrainian Science and Technology Center (USTC) (funded by the United States and Canada).

The contract No. 247 “The development of manufacturing processes and design methods for radiant energy concentrators using technologies and design techniques for rocket and space technology” (1997-1999), the department carried out independently; the contracts No. 4133 (2006 – 2008) – with the Frantsevich Institute for Problems of Materials of the NASU, No. 4876 (2010 – 2012) – with other departments of the ITM of the NASU and SSAU.

The results of some studies are implemented in the calculation and production practice of enterprises of rocket and space and aviation equipment, energy, construction.

Works on the research areas mentioned were honoured with:

- 1997 State Prize of Ukraine in Science and Technology for a series of works on the development of up-to-date methods for assessment of the strength and durability of structural elements of modern equipment and the preparation of normative documents based thereon (Hudramovich V. S. – as a member of the group of authors of Pisarenko Strength Problems Institute of the National Academy of Sciences of Ukraine, the National Academy of Sciences of Belarus);
- 1997 Yangel Prize of the National Academy of Sciences of Ukraine for the series of works “Development of Experimental-Theoretical Methods and Study of the Longevity of Space Hardware” (Hudramovich V.S., Pereverzev E.S.);
- 2004 Timoshenko Prize of the National Academy of Sciences of Ukraine for the series of works “Material Deformation Processes and Limiting States of Structural Elements under Complex Loading” (Hudramovich V.S. – as a member of the group of authors of Pisarenko Strength Problems Institute of the NASU).

Department scientists were awarded with:

- “For scientific achievements” badge of honour from the Presidium of the National Academy of Sciences of Ukraine (Hudramovich V.S.);
- “Excellence in Education” badge of honour from the Ministry of Education and Science of Ukraine (Hudramovich V.S.).
- medal named after Yu. V. Kondratyuk of the Federation of Cosmonautics of Ukraine (Hudramovich V.S.);
- medal named after acad. M.K. Yangel of the USSR Astronautics Federation (Hudramovich V.S.);
- medal to the 60th anniversary of Yuzhnoye State Design Office named after M.K. Yangel (Hudramovich V.S.);
- medal to the 100th anniversary of M.K. Yangel (Poshivalov V.P.);
- medal “For loyal service” of DNU (Hudramovich V.S.);
- medal “Academician Vladimir Mossakovsky”, DNU (Hudramovich V.S.);
- III degree diploma (6th All-Ukrainian competition of scientific works of the Society of Non-Destructive Testing and Technical Diagnostics of Ukraine) (Hudramovich V.S.);
- award “For Achievements” ITM of the NASU and SSAU (Hudramovich V.S.);
- medal to the centenary of the birth of V.I. Mossakovsky (Hudramovich V.S.);
- gratitude and diploma of the Dnieper Scientific Center of the National Academy of Sciences of Ukraine and the Ministry of Education and Science of Ukraine on the occasion of the celebration of Science Day (Reprintsev O.V., Telegina I.I.).

OFFICE ADDRESS: | Institute of Technical Mechanics, 15, Leshko-Popelya St., Dnipro, Ukraine, 49005 |

PHONE NUMBER: | +(380)-56-376-45-86 |

FAX NUMBER: | +(380)-56-376-45-86 |

E-MAIL: | poshivalov.v.p@nas.gov.ua vposhivalov@gmail.com |