YUAN Ke,GAO Dong,YIN Mei,et al. Study on the influence of sample size and roughness on fatigue performance of 7085 aluminum alloy[J].Journal of Mechanical Strength,2025,47(7):80-85.
YUAN Ke,GAO Dong,YIN Mei,et al. Study on the influence of sample size and roughness on fatigue performance of 7085 aluminum alloy[J].Journal of Mechanical Strength,2025,47(7):80-85. DOI: 10.16579/j.issn.1001.9669.2025.07.010.
Study on the influence of sample size and roughness on fatigue performance of 7085 aluminum alloy
The fatigue limit of 7085 aluminum alloy was tested by four-point bending fatigue test for samples of different sizes and roughness.The results show that the greater the thickness of the specimen
the greater the ultimate fatigue strength of the material. The higher the surface roughness of the sample
the lower the ultimate fatigue strength of the material. The stress analysis and calculation of the specimen show that the dangerous cross section occurs at the position where the indenter contacts the specimen
where the specimen is subjected to the combined action of bending normal stress and shear force. With the increase of the thickness of the specimen
the shear force on the specimen decreases
and the bending normal stress on the specimen increases under the same fatigue limit. And vice versa. The relation between the surface roughness and the radius of curvature of the sample is shown by establishing a simplified model
and then the relationship between the surface roughness and the fatigue ultimate strength of the material is obtained.
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