Influence of operational factors on the patterns of distribution of discrete deformations of the surface layer of metal structures for multi-cycle loading of samples

Authors

  • A. M. Mailo Інститут проблем міцності імені Г.С. Писаренка НАН України, Ukraine https://orcid.org/0000-0002-4762-0886
  • G. G. Pysarenko Інститут проблем міцності імені Г.С. Писаренка НАН України, Ukraine
  • O. V. Voinalovych Національний університет біоресурсів і природокористування України, Ukraine

DOI:

https://doi.org/10.20535/2521-1943.2018.84.136382

Keywords:

fatigue, inelasticity, microplastic strains, deformation relief, speckle pattern

Abstract

The structural material heterogeneity causes the scatter in the mechanical properties. The local stresses in the crystallite can exceed by several times the actual stress values. The order of magnitude of the microplastic strains is 10-6 mm/mm, which is below the fatigue limit at normal stresses. Due to the structural and technological factors, the surface elasto-plastic layer of the structural material is less resistant to mechanical damage than the bulk of the material, resulting in a certain number of fatigue failure cases in the total number of failures of metal structures. Non-uniformities in the micro-stress state lead to an irregular development of micro-plastic strains, whose localization affects the evolution of a dissipative structure in a polycrystalline material, which is particularly critical for the subsurface layer. The analysis of the damage state evolution for structure-sensitive parameters of the substructure surface makes it possible to control the mechanical properties of the structural material under high-cycle deformation

References

  1. Bathias, C. (1999), “There is no infinite fatigue life in metallic materials”, Fatigue & fracture of engineering materials & structures, Vol. 22, no. 7, pp. 559–565.
  2. Bydzan, A. and Panin, S. (2000), “Fatigue failure as process of sequential development of plastic deformation and continuity disturbance in hierarchy of structural levels”, The 4th Korea-Russia International Symposium On Science and Technology, Ulsan, South Korea, June 27-July 1 2000, pp. 337–341.
  3. Alfyorova, E.A. and Lychagin, D.V. (2018), “Self-organization of plastic deformation and deformation relief in FCC single crystals”, Mechanics of Materials, Vol. 117, pp. 202–213.
  4. Schreiber, J., Cikalova, U., Hillmann, S., Hoffmann, J. and Meyendorf, N. (2012), A fatigue life assessment of aircraft alloys using fractal analysis in combination with eddy current testing, Available: https://www.ndt.net/article/wcndt2012/papers/240_wcndtfinal00240.pdf.
  5. Kossov, V.S., Oguenko, V.N. and Oguenko, V.V. (2007), “Accounting of giga-cycle fatigue of steel in assessing the service life of critical parts of railway equipment”, Science and Transport Progress, Vestnik Dnepropetrovskogo natsional'nogo universiteta zheleznodorozhnogo transporta, no. 19, pp. 165–169.
  6. Vladimirov, A.P., Kamantsev, I.S., Veselova, V.E., Gorkunov, E.S. and Gladkovskii, S.V. (2016), “Using dynamic speckle interferometry for non-contact diagnosis of the nucleation of a fatigue crack and determining the rate of its growth”, Zhurnal Tekhnicheskoi Fiziki, no. 4, pp. 85–90.
  7. Mineev, S.A., Ugol'nikov, A.Yu. and Lozovskaya, L.B. (2014), “Speckle-imaging technique to study a deformable surface by optical flow algorithms”, Vestnik Nizhegorodskogo universiteta im. N.I. Lobachevskogo, no. 2, pp. 81–86.
  8. Meireles, J.B., da Silva, L., Caetano, D.P. and Huguenin, J.A.O. (2008), “Effect of metallic surface roughness on the speckle pattern formation at diffraction plane”, Optics and Lasers in Engineering, no. 12, pp. 1731–1734.
  9. Shih-Heng, T., Ming-Hsiang, S. and Wen-Pei, S. (2008), “Development of digital image correlation method to analyse crack variations of masonry wall”, Sadhana, no. 6, pp. 767–779.
  10. Sergeev, R.N. and Kharchikova, Yu.V. (2012), “Mobile digital speckle interferometry with cw lasers deformation field for registration of movements and flaw structural materials”, Izvestiya Samarskogo nauchnogo tsentra Rossiiskoi akademii nauk, no. 4, pp. 216–220.

Published

2018-12-26

How to Cite

[1]
A. M. Mailo, G. G. Pysarenko, and O. V. Voinalovych, “Influence of operational factors on the patterns of distribution of discrete deformations of the surface layer of metal structures for multi-cycle loading of samples”, Mech. Adv. Technol., vol. 84, no. 3(84), pp. 39–44, Dec. 2018.

Issue

Section

Original study