کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
768901 897358 2011 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of the load ratio on the threshold stress intensity factor range for heavily drawn steel wires
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی صنعتی و تولید
پیش نمایش صفحه اول مقاله
Influence of the load ratio on the threshold stress intensity factor range for heavily drawn steel wires
چکیده انگلیسی

The fatigue behavior of heavily drawn steel wires with a diameter of 175 μm and total strain of 3.5 has been studied. A new approach is used to estimate the threshold stress intensity factor range for crack growth (ΔKth,R) which is based on fatigue crack initiations at internal non-metallic inclusions. At these internal crack initiations a characteristic area is formed around the inclusion (in literature this region is called optical dark area, granularly bright facet or facet). This area corresponds to the short crack growth regime. The transition between short and long crack growth, which can be seen clearly by fractography, is used to estimate ΔKth,R.ΔKth,R is estimated for different stress amplitudes (σa) and load ratios (R). It is observed that ΔKth,R is independent of σa and that the fatigue crack growth is Kmax controlled for R < 0.15 and ΔK controlled for R > 0.15. The two asymptotes of the (ΔK, Kmax) graph, ΔKth∗ and Kmax∗, are calculated to be 3.82 ± 0.09 and 4.47 ± 0.16 MPa √m respectively.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Engineering Failure Analysis - Volume 18, Issue 2, March 2011, Pages 694–699
نویسندگان
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