scholarly journals MODELS OF PHYSICALLY SHORT AND MACROSCOPIC CRACK DEVELOPMENT AND THEIR APPLICATION FOR TIN BASED BABBIT

2019 ◽  
Vol 2019 (5) ◽  
pp. 4-14
Author(s):  
Михаил Зернин ◽  
Mikhail Zernin
Keyword(s):  
Fatigue Crack ◽  
Crack Resistance ◽  
Cyclic Crack Resistance ◽  
Crack Development ◽  
Generalized Model ◽  
Short Cracks ◽  
Macroscopic Crack ◽  
Fatigue Crack Development

The stages of fatigue crack development are analyzed. The well-known models of physically short cracks and generalized models describing some stages are shown. A perspectivity of a statistical generalized model offered is shown. The parameters obtained of a cyclic crack resistance of tin-based babbit are presented.

Test Stand for Analysis of Fatigue Crack Propagation under Bending with Torsion

2008 ◽  
Vol 144 ◽  
pp. 90-93 ◽  
Author(s):  
Grzegorz Gasiak ◽  
Grzegorz Robak
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Digital Camera ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Test Stand ◽  
Crack Development ◽  
Fatigue Crack Propagation Rate ◽  
Fatigue Crack Development

The paper presents a test stand for measurements of fatigue crack propagation. The stand includes a fatigue machine MZGS–100 and a device for registration of the crack length. The test stand is equipped with a stereoscopic microscope with fluent magnification of 7× – 67.5×. The microscope can be applied for observation of fatigue crack development. The microscope is also equipped with a digital camera, which enables continuous observation of fatigue crack development on the computer monitor and it is not necessary to stop the machine. The test results obtained at this stand can be used for determination of fatigue life and fatigue crack propagation rate.

Fractography and fatigue crack development kinetics in cast iron crankshafts

1983 ◽  
Vol 15 (5) ◽  
pp. 691-695
Author(s):  
V. A. Stepanenko ◽  
N. N. Sultani ◽  
V. V. Khil'chevskii ◽  
Yu. M. Shemegan
Keyword(s):  
Fatigue Crack ◽  
Cast Iron ◽  
Crack Development ◽  
Fatigue Crack Development

Creep–fatigue crack development from short crack starters

2014 ◽  
Vol 31 (4) ◽  
pp. 305-314 ◽  
Author(s):  
W-. T. Yan ◽  
S. Holdsworth ◽  
I. Kühn ◽  
E. Mazza
Keyword(s):  
Fatigue Crack ◽  
Crack Development ◽  
Short Crack ◽  
Creep Fatigue ◽  
Fatigue Crack Development ◽  
Creep Fatigue Crack

scholarly journals EVALUATION OF CHARACTERISTICS OF RESISTANCE OF PROPAGATION OF CORROSION- FATIGUE CRACKS OF LONG-TERM OPERATED DRILL PIPES

2021 ◽  
pp. 111-122
Author(s):  
О. Yu. Vytyaz ◽  
R. S. Hrabovskyi
Keyword(s):  
Fatigue Crack ◽  
Crack Resistance ◽  
Corrosion Fatigue ◽  
Fatigue Cracks ◽  
Drill String ◽  
Drilling Mud ◽  
Corrosion Fatigue Crack ◽  
Corrosion Crack Resistance ◽  
Fatigue Crack Development

The aim of the proposed article is to determine the patterns of the corrosion-fatigue cracks in long-term operational metal elements of drill strings (steel 45, 36G2S, 40HN) when drilling wells in corrosive environments (drilling fluid "Biocar", potassium polymer mud and on the air). Based on the obtained results of experimental studies, diagrams of cyclic corrosion crack resistance for the studied systems "metal - medium" were drawn. The cyclic crack resistance characteristics of long-used metals of drill string elements are determined - the values of constants (C and n) in power dependence of Paris, as well as the values of threshold and critical stress intensity factory. The influence of drilling mud of the corrosion crack resistance of the investigated metals of drill string elements was estimated quantitatively. In particular, in the environment of drilling mud "Biocar" the process of corrosion-fatigue crack development in the studied metals of the elements of drill strings is not significantly, in the range of 1-5%, differs from the development of fatigue crack on the air. Whereas in the potassium polymer drilling mud media, the rate of corrosion-fatigue cracks development in the investigated metals of the drill strings elements significantly, in the range of 15-35%, differs from the development of fatigue cracks on the air. It is established that under the influence of working loads the process of the corrosion-fatigue crack development in long-operated elements of drilling string is accelerated by more than 10% in the media of the potassium polymeric drilling mud than in the environment of drilling mud "Biocar".

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