VESTNIK of Samara University. Aerospace and Mechanical EngineeringVESTNIK of Samara University. Aerospace and Mechanical Engineering2542-04532541-7533Samara National Research University247410.18287/1998-6629-2014-0-5-1(47)-9-17UnknownConception of cycle life additivity and its application for determining the resource of aero engine disksTumanovN. V.<p>Candidate of Science (Engineering)</p>
<p>Head of Sector</p>tumanov@rtc.ciam.ruLavrentyevaM. A.<p>Leading Designer</p>psn@ciam.ruCentral Institute of Aviation Motors20122014135-19170906201509062015Copyright © 2015, VESTNIK of the Samara State Aerospace University2015<p>Taking into account the universal character and high energy intensity of the mechanism of low cycle fatigue(LCF) crack stable growth which ensures a long safety period for the growth of such cracks a conception of cyclelife additivity is proposed. According to the conception the cycle life of an aero engine disk is determined up to thelimiting state connected with the transition of a LCF crack to unstable growth in the critical area of a disk. The cyclelife prior to the first overhaul is calculated by adding the life cycle before the crack origination and that of stablecrack growth (survivability resource); the overhaul period is determined by the survivability resource. The latter isalso the lower bound of the disk life at the design stage. To estimate the overhaul period we suggest using survivabilitydiagrams representing the dependence of LCF crack stable growth in the critical area of the disk on the size ofthe crack. Methods of constructing survivability diagrams have been developed for simple and complex loadingcycles. Examples of applying the conception for the estimation of cycle life of aero engine disks made of wroughtand powder alloys are presented.</p>Сycle lifeaero engine diskslimiting stateslow cycle fatiguestable growth of fatigue cracksЦиклическая долговечностьпредельные состояниядиски авиадвигателеймалоцикловая усталостьустойчивый рост усталостных трещин[1. Tumanov N.V. Fatigue crack kinetic stages and mechanism of periodic splittingrupture // Proceedings of the 1st International Conference «Deformation and fracture of materials». V. 1. Moscow: IMET RAN Publ., 2006. P. 85-87. (In Russ.)][2. Tumanov N.V., Lavrentyeva M.A., Cherkasova S.A. Reconstitution and prediction of fatigue crack propagation in aero engine disks // Conversion in machine building of Russia. 2005. No. 4-5. P. 98-106. (In Russ.)][3. Tumanov N.V., Lavrentyeva M.A., Cherkasova S.A., Servetnik A.N. Modeling stable growth of fatigue cracks in aero engine turbine disks under simple and complex loading cycles // Vestnik of the Samara State Aerospace University. 2009. No. 3(19), part 1. P. 188-199. (In Russ.)][4. Tumanov N.V. Physical and mechanical aspects of fatigue crack stable growth // Vestnik Moskovskogo aviatsionnogo instituta. 2011. V. 18, no. 2. P. 132-136. (In Russ.)][5. Nozhnitsky Yu.A., Tumanov N.V., Cherkasova S.A., Lavrentyeva M.A. Fractogrphic methods of residual life estimation for aero engine disks // Vestnik UGATU. 2011. V. 15, no. 4(44). P. 39-45. (In Russ.)][6. Tumanov N.V., Cherkasova S.A., Lavrentyeva M.A., Vorobyeva N.A. Study of mechanisms of low cycle fatigue crack propagation in aero engine disks under operating conditions and disk residual life estimation // Vestnik of the Samara State Aerospace University. 2011. No. 3(27), part 2. P. 175-184. (In Russ.)][7. Bolotin V.V. Resurs mashin i konstruktsiy [Life of machines and structures]. Moscow: Mashinostroyeniye Publ., 1990. 448 p.][8. Makhutov N.A. Konstruktsionnaya prochnost', resurs i tekhnogennaya bezopasnost' [Structural integrity, life and technotronic security]. V. 2. Life and safety substantiation. Novosibirsk: Nauka Publ., 2011. 610 p.][9. Tumanov N.V., Lavrentyeva M.A., Cherkasova S.A. Prediction of residual life of aero engine turbine disks based on the calculation of low cycle fatigue crack stable growth // Vestnik MAI. 2011. V. 18, no. 5. P. 33-41. (In Russ.)]