Перегляд за Автор "Naumenko, Konstantin"
Зараз показуємо 1 - 4 з 4
Результатів на сторінці
Налаштування сортування
Документ Inelastic Deformation of Conductive Bodies in Electromagnetic Fields(Springer Berlin Heidelberg, 2016) Altenbach, Holm; Morachkovsky, Oleg; Naumenko, Konstantin; Lavinsky, D. V.Inelastic deformation of conductive bodies under the action of electromagnetic fields is analyzed. Governing equations for non-stationary electromagnetic field propagation and elastic-plastic deformation are presented. The variational principle of minimum of the total energy is applied to formulate the numerical solution procedure by the finite element method. With the proposed method, distributions of vector characteristics of the electromagnetic field and tensor characteristics of the deformation process are illustrated for the inductor-workpiece system within a realistic electro-magnetic forming process.Документ Influence of the element type on the accuracy of creep-damage predictions in thin-walled structures(Cracow University of Technology, 2001) Naumenko, Konstantin; Altenbach, Holm; Huang, Chunxiao; Burlayenko, Vyacheslav. N.Based on the continuum creep-damage mechanics and the finite element analysis the long-term strength in thin-walled structures is estimated using the solid and the shell type finite elements available in ANSYS code. For this purpose the material model with a scalar damage parameter is incorporated into the ANSYS code with the help of a user defined material subroutine. The results based on the first order shear deformation beam equations are compared with the results of the finite element plane stress simulations. It is demonstrated that the shear correction factor and the distribution function of the transverse shear stress have to be modified within time-step calculations. For a rectangular plate in bending finite element analysis is performed based on the shell and the solid type finite elements. The differences in the edge-zone stress redistributions in the shell and the solid type models as well as the influence of boundary layer solutions on the long-term predictions are illustrated.Документ Kontaktwechselwirkung einer Rohrleitung mit der Reparaturbandage aus einem Kompositwerkstoff(Springer, 2014) Beschetnikov, Dmitriy A.; Lvov, Gennadiy I.; Naumenko, Konstantin; Sukiasov, Vladimir G.; Altenbach, HolmIn der vorliegenden Arbeit wird die Kontaktaufgabe über die Wechselwirkung einer langen Zylinderschale mit einer koaxialen zylindrischen Bandage aus einem Verbundwerkstoff untersucht. Der Verbundwerkstoff wird als ein homogenes orthotropes Material mit bekannten effektiven elastischen Eigenschaften modelliert. Basierend auf der klassischen Schalentheorie werden die Grundgleichungen für die Kontaktaufgabe sowie allgemeine Lösungen für die Durchbiegungen und Schnittgrößen formuliert. Die unbekannten Integrationskonstanten sowie die Kontaktfläche werden numerisch mit Hilfe des Programmpakets Maple ermittelt. Drei charakteristische Längen der Bandage, bei denen der Übergang von einemKontaktschema der Wechselwirkung zu einem anderen erfolgt, wurden ermittelt. Es wurde festgestellt, dass die Änderung des Innendrucks nicht zum Übergang von einem Kontaktschema zu einem anderen führt. Der Charakter der Kontaktwechselwirkung wird durch geometrische Parameter derVerbindung und elastische Materialeigenschaften der Schale und der Bandage bestimmt.Документ Modelling of Creep and Oscillations in Material Described by Armstrong-Frederick Equations(NTU "KhPI", 2016) Breslavsky, Dmitry; Altenbach, Holm; Naumenko, Konstantin; Tatarinova, OksanaDifferent structural elements at high temperatures and cyclic loading demonstrate essential creep behavior. Due to variety of materials which are used in modern industrial applications the different forms of creep response have to be analyzed. The one of them presents in materials are characterized by creep processes with essential recovery, which is expressed by strain decreasing after the unloading. Such material behavior is described by well-known Armstrong-Frederick model. The case of cyclic loading leading to forced oscillations at high temperature is studied. The Armstrong- Frederick creep model contains two equations: first for creep strain rate function as well as the second for socalled backstress evolution. The problem is solved by two time scales methods with subsequent averaging in a period of oscillations. The solution was performed for the hyperbolic creep strain rate function which satisfactory describes the high-temperature behavior of advanced steel with primary creep conditions. The stress function is presented by expansion in Fourier series. Asymptotic solution of creep equations was obtained and by use of the procedure of averaging in the period the new model describing ‘slow’ creep motion has been derived. The analytical forms of influence functions for both equations of the model expressing the role of cyclical loading were obtained. Numerical examples which demonstrate the cyclic creep behavior in advanced steel X20CrMoV12-l are presented and discussed.