Discrete Properties of the Inelasticity of Steel and Alloys Based on Al and Ti under Periodic Deformation
G. G. Pisarenko$^{1}$, О. V. Voynalovich$^{2}$, A. M. Mailo$^{1}$
$^{1}$G. S. Pisarenko Institute for Problems of Strength, NAS of Ukraine, 2 Timiryazevs’ka Str., UA-01014 Kyiv, Ukraine
$^{2}$National University of Life and Environmental Sciences of Ukraine, 15 Heroiv Oborony Str., UA-03041 Kyiv, Ukraine
Received: 13.05.2019; final version - 08.10.2019. Download: PDF
The paper presents the amplitude characteristics of the dissipative properties of steel and alloys under different conditions of deformation of laboratory samples obtained by the method of the normalized range of amplitudes of discrete deformations. Amplitude characteristics of the discrete properties of the surface of a laboratory sample material are compared in a wide range of strain amplitudes. Using the developed contact-resonance method for measuring discrete inelastic deformations of the surface layer of a material, the kinetic characteristics of scattered damage to light alloys are obtained, where the instability of inelastic deformations manifests itself during periodic loading in the form of material hardening–softening processes. The revealed repeatability of extremums of the kinetic characteristics of inelasticity shows a stochastic regularity studied in the work. The systematization of the results of the study allows us to reveal the correlation of the characteristics of the inelastic deformations of the surface of the loaded metal with cyclic durability. On the basis of experimental and calculated data within the framework of the structural-energetic theory of fatigue, the use of a recurrent series to determine the durability by the hardening criterion is substantiated. As a result of scanning the surface of samples of the material, the amplitude characteristics of the deformation of the local volumes of material in the scanning zone are obtained. The amplitude scan spectrum corresponding to the state of deformation defects of the surface represents the general totality of the results determined by the method of normalized magnitude. It combines the results of a series of consecutive measurements of inelastic deformations developed in the subsurface layer of the material of a laboratory sample with a monotonic increase in the intensity of the degree of scattered damage in the process of high-cycle loading.
Key words: fatigue, inelasticity, bifurcation point, scattered damage, Hurst index.
URL: http://mfint.imp.kiev.ua/en/abstract/v42/i02/0261.html
DOI: https://doi.org/10.15407/mfint.42.02.0261
PACS: 05.65.+b, 46.50.+a, 62.20.F-, 62.20.M-, 81.40.Jj, 81.40.Np
Citation: G. G. Pisarenko, О. V. Voynalovich, and A. M. Mailo, Discrete Properties of the Inelasticity of Steel and Alloys Based on Al and Ti under Periodic Deformation, Metallofiz. Noveishie Tekhnol., 42, No. 2: 261—279 (2020) (in Russian)