Inhomogeneities and Extreme Fluctuations of Strains in Grains of Polycrystalline Materials

21st Winter School on Continuous Media Mechanics

计算机技术

Shavshukov, V.E.^1 ; Tashkinov, A.A.^1

Perm National Research Polytechnic University, 29 Komsomolsky Av., Perm

614990, Russia^1

关键词: Damage initiation;    Individual grains;    Inhomogeneities;    Non-uniformities;    Polycrystalline samples;    Random microstructure;    Strain fluctuations;    Theoretical approach;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/581/1/012032/pdf
DOI  :  10.1088/1757-899X/581/1/012032

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

Inhomogeneity of strains in individual grains are calculated using the field-theoretical approach in the mechanics of polycrystalline materials. It is shown that the microstructure surrounding the grain strongly influences the amplitude of the non-uniformity of strains in the grain. In the random microstructure of a polycrystal, there are specific clusters of grains in which very large strain fluctuations are realized. The strains in these clusters exceed macrostrains several times. The patterns of such extreme clusters are presented. Extreme strain fluctuations in bulk grains exceed fluctuations in surface grains by 40%. This may be one of the reasons for the movement of sites of damage initiation in gygacycle fatigue mode from the surface of a polycrystalline sample into the bulk.