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Estimation of Design Thermal Integrity

  • Boris F. ShorrEmail author
Chapter
Part of the Foundations of Engineering Mechanics book series (FOUNDATIONS)

Abstract

Working capacity of machine parts in various possible operation conditions must be maintained by introduction of strength and durability margins (safety factors). These margins are necessary in view of possible random industrial deviations, unforeseen adverse combinations of loads, temperatures, and operating time at some regimes, and many other reasons. General principles for safety factor formation require analyzing the most probable ways for deviation of stresses, temperatures, and work duration or any other specific parameter, over its design value—on separateness or in aggregate with other ones. The possibility of creating a design of “equal strength” at non-isothermal loading is illustrated by the optimization of a turbomachine blade model non-uniformly heated along its length. The benefits of introducing a “weak link” that reaches destruction under overload before the entire system are discussed. It is shown that “equivalent” trials replicating the lifetime of the system can significantly accelerate the verification of the most stressed machine parts. The trials ensure a machine functioning with the same safety factors as under the work conditions, but during smaller duration. The cyclic durability margins for non-isothermal cyclic fatigue, taking into account influence of exposure at the maximum cycle temperature and asymmetric loading, are considered. Along with the evaluation of local strength and durability margins for the most stressed elements of a structure, computation methods, on a bearing ability of the structure “in whole,” are stated. Use of the determined safety factors is shown to be principally necessary for the reliable probabilistic estimation of details’ low-cycle fatigue (LCF). For this purpose, rational methods for generation of probabilistic-statistical strength and durability margins of machine parts, using results of the limited scope of sampling tests, are proposed.

Keywords

Safety Factor Bearing Capacity Machine Part Strength Margin Temperature Margin 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. Birger IA (1948) Strength margins at variable stresses. Vestnik Mashinostroeniya, No.6. Moscow, pp 5–14 (in Russian)Google Scholar
  2. Birger IA (1970) Damage probability, strength margins and diagnosis. Problems of solid mechanics. Sudostroenie, Leningrad, pp 70–81 (in Russian)Google Scholar
  3. Birger IA, Shorr BF (eds) (1975) Thermal strength of machine parts. Mashinostroenie, Moscow (in Russian)Google Scholar
  4. Birger IA, Shorr BF, Iosilevich GB (1993) Strength design of machine parts, 4th ed. Mashinostroenie, Moscow (in Russian)Google Scholar
  5. Birger IA, Shorr BF, Shneyderovich RM (1969) Designing machine parts for strength. Foreign Technology Division Wright–Peterson AFB OHTO. Ft. Belvoir Defense Technical Information Center (Trans. from Russia, 2nd ed, 1966). Mashinostroenie, MoscowGoogle Scholar
  6. Bolotin VV (1965) Statistical methods in structural mechanics. Stroyizdat, Moscow (in Russian)Google Scholar
  7. Dul’nev RA (1971) Damage summation and strength condition at thermocycle loading. Problemy Prochnosty 10:101–104 (in Russian)Google Scholar
  8. Karimbaev KD, Starodubtzev VV (2010) To design verification of disk bearing capacity. In: Theses of reports at VI International scientific conference, Orenburgskiy Gos. Universitet, Orenburg, pp 185–191 (in Russian)Google Scholar
  9. Nozhnitsky YuA, Lokshtanov EA, Dolgopolov IN et al (2006) Probabilistic prediction of aviation engine critical parts lifetime. In: Proceedings of GT2006 ASME Turbo Expo 2006; Power for Land, Sea and Air, GT2006-91350, Barselona, SpainGoogle Scholar
  10. Serensen SV, Kogaev VP, Shneyderovich RM (1963) Loadability and strength calculation of machine structures, 1st ed (3rd ed 1975). Mashinostroenie, Moscow (in Russian)Google Scholar
  11. Servetnik AN (2012) Load-carrying capability simulation of aviation gas turbine engine disks. In: Engineering Journal Handbook, vol 10, pp 44–49 (in Russian)Google Scholar
  12. Shorr BF, Kochukov NS, Porter MA (1970) Accelerated equivalent tests of operational reliability of welded machine parts. J. Problemy Prochnosty 2:63–67Google Scholar
  13. Shorr BF, Lokshtanov EA, Khalatov YuM (1972) On a possible approach to probabilistic estimation of vibration strength of turbomachine details. J Problemy Prochnosty 11:11–14 (in Russian)Google Scholar
  14. Velikanova NP (1990) Effect of engine operating time on turbine disk strength. In: Proceedings of International Conference on ICAE-90, Moscow-Zagorsk, CIAM, pp 90–97Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Central Institute of Aviation Motors (CIAM)MoskvaRussia

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