کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5015305 1463733 2016 38 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mean stress sensitivity and crack initiation mechanisms of spring steel for torsional and axial VHCF loading
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی مکانیک
پیش نمایش صفحه اول مقاله
Mean stress sensitivity and crack initiation mechanisms of spring steel for torsional and axial VHCF loading
چکیده انگلیسی
The very high cycle fatigue (VHCF) properties of shot-peened VDSiCr spring steel have been investigated with the ultrasonic fatigue testing method. Fatigue behaviour under cyclic torsion and cyclic tension loading at load ratios between R = −1 and R = 0.5 is compared. For 90% of the VHCF failures under axial loading, fractured grain boundaries or inclusions in the interior of the material act as crack starters. In contrast, the initial crack is produced by cyclic shear in the interior or, less frequently, at the surface for more than 90% of the VHCF failures under torsional loading. The crack path deflects from mode II/mode III to mode I at the border of the initiating shear area. The change of crack path correlates to a stress intensity factor range for a crack loaded in shear mode of ΔKτ,ISA = 5.6 ± 0.5 MPam1/2 for load ratio R = 0.1 and ΔKτ,ISA = 3.8 ± 0.4 MPam1/2 for R = 0.35, respectively. Residual stresses due to shot-peening are stable during VHCF axial loading while they are reduced during VHCF torsional loading.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Fatigue - Volume 93, Part 2, December 2016, Pages 309-317
نویسندگان
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