Authors & Affiliations
Vilensky O.Yu., Lapshin D.A., Malygin M.G., Pristrom S.A.
Afrikantov Experimental Design Bureau for Mechanical Engineering, Nizhny Novgorod, Russia
Lapshin D.A. – Head of design group, Cand. Sci. (Tech.), Afrikantov Experimental Design Bureau for Mechanical Engineering.
Malygin M.G. – Head of design group, Afrikantov Experimental Design Bureau for Mechanical Engineering.
Pristrom S.A. – Head of design group, Afrikantov Experimental Design Bureau for Mechanical Engineering.
The paper provides the main results of deformation process analysis and assessment of consequences of roof block dropping on the BN-600 reactor under operation.
The dropping scenario, regarded as abnormal operation initiating event, has been defined.
Dropping computational analysis is carried out using dynamic analysis module LS-DYNA of certified ANSYS program package. The LS-DYNA module is intended for computational analysis of highly linear dynamic processes using explicit scheme of dynamic equation integration. The paper describes computational and experimental methods aimed at analyzing models of deformation of structural ma-terials under the impact of static and dynamic loads and defines based on experimental studies the parameters of Jonson-Cook model from LS-DYNA library.
Mathematical analysis employs a verified model of behavior of the structural material used in BN-600 reactor pressure vessel.
The obtained results made it possible to analyze the dropping process, define the plastic deformations that occur in all component parts of the reactor and the loads acting upon the support structures.
The assessment of the consequences of roof block dropping on the reactor allowed us to conclude that the reactor vessel and in-vessel structures preserve their integrity and remain operable under internal dynamic impacts.
The application of a comprehensive approach implemented in this computational analysis made it possible to solve the problem related to reactor operation safety assurance under conditions when equipment falls onto the reactor applying moderate conservatism.
dynamic processes, reactor vessel, plastic deformation, assessment of dropping process consequences, safe operation and deformation model
1. ANSYS Program Package. Software Tool Certification Passport no. 327, 2013.
2. Hallquist J.O. LS-DYNA theoretical manual.Livermore, Livermore Software Technology Corporation, 1998.
3. LS-DYNA 960 Keyword User’s Manual. Livermore, Livermore Software Technology Corporation, 2001.
4. Lapshin D.A. Raschetno-eksperimental’nyy analiz prochnosti vnutriob”yektovykh transportnykh konteynerov reaktorov tipa BN v avariyakh s padeniyem. Diss. kand. tekhn. nauk [Computational and Experimental Analysis of Strength of In-Facility Transportation Casks of BN Reactors in Accidents with Dropping. Cand. techn. sci. diss.]. Nizhny Novgorod, 2015.
5. Kolskiy G. Issledovaniye mekhanicheskikh svoystv materialov pri bol’shikh skorostyakh nagruzheniya [Study of Mechanical Properties of Materials at High Rates of Loading]. Mekhanika - Mechanics, 1950, no. 4, pp. 108–119.
6. Bragov A.M., Lomunov A.K. Osobennosti postroyeniya diagramm deformirovaniya metodom Kol’skogo [Specific Characteristics of Plotting Deformation Diagrams Using the Kolskiy Method]. Gorky, University of Gorky, 1984. Pp. 125–137.
7. Bragov A.M., Lomunov A.K. Methodological aspects of studying dynamic material properties using the Kolsky method. International Journal of Impact Engineering, 1995, vol. 16, no. 2, pp. 321–330.
8. Nicholas T. Tensile testing of materials at high rates of strain.Experimental Mechanics, 1981, vol. 21, no. 5, pp. 177–195.
9. Bragov A.M. Eksperimental’nyy analiz protsessov deformirovaniya i razrusheniya materialov pri skorostyakh deformatsii 102–105s-1 Dis. dokt. tekhn. nauk [Experimental Analysis of Deformation and Failure Processes of Materials at Deformation Rates Equal to 102-105 s-1. Dr. techn. sci. diss.]. Nizhny Novgorod, 1998.
10. Johnson G.R., Cook W.H. A constitutive model and data for metals subjected to large strains, high strain rates and high temperatures. Proc. 7th Int. Symposium on Ballistic. Hague, Netherlands, 1983, pp. 541–547.
11. Taylor G.I., Quinney H. The latent energy remaining in a metal after cold working. Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 1934, vol. 143, no. 849, pp. 307-326.
12. Huh H., Kang W.J. Crash-Worthiness Assessment of Thin-Walled Structures with the High-Strength Steel Sheet. International Journal of Vehicle Design, 2002, vol. 30, no. 1/2.
13. Allen D.J., Rule W.K., Jones S.E. Optimizing Material Strength Constants Numerically Extracted from Taylor Impact Data.Experimental Mechanics, 1997, vol. 37, no. 3.
14. Cowper G.R., Symonds P.S. Strain Hardening and Strain Rate Effects in the Impact Loading of Cantilever Beams. Brown University, Applied Mathematics Report, 1958.
15. Konstantinov A.Yu. Eksperimental’no-raschetnoye issledovaniye povedeniya konstruktsionnykh materialov pod deystviyem dinamicheskikh nagruzok. Diss. kand. tekhn. nauk. [Experimental and Analytical Study of Structural Materials Behavior under the Impact of Dynamic Loads. Cand. techn. sci. diss.]. Nizhny Novgorod, 2007.
16. Kotov V.L., Konstantinov A.Yu., Kibets Yu.I., Tarasova A.A., Vlasov V.P. Hislennoye modelirovaniye ploskoparallel’nogo dvizheniya konicheskikh udarnikov v uprugoplasticheskoy srede [Numerical Simulation of Plane-Parallel Motion of Tapered Hammers in Elastoplastic Medium].Problemy prochnosti i plastichnosti - Problems of strength and ductility, 2013, vol. 75, no. 4, pp. 303-311.
17. Rodriguez T., Navarro C., Sanchez-Galvez V. Splitting tests: an alternative to determine the dynamic tensile strength of ceramic materials.Journal de Physique IV, 1994, pp.101–106.
18. PNAE G-7-002-86. Normy rascheta na prochnost’ oborudovaniya i truboprovodov atomnykh energeticheskikh ustanovok [Standards of Strength Analysis of Equipment and Pipelines of Nuclear Power Facilities]. Moscow, Energoatmizdat Publ., 1989. 525 p.
19. Nadai A. Plastichnost’ i razrusheniye tverdykh tel[Ductility and Failure of Solid Bodies]. Moscow, Publisher of Foreign Literature, 1954.
20. Karzov G.P., Margolin B.Z., SHvetsova V.A.Fiziko-mekhanicheskoye modelirovaniye protsessov razrusheniya [Physical and Mechanical Simulation of Failure Processes]. St. Petersburg, Politekhnika Publ., 1993. 391 p.