Effect of loading frequency and cycle asymmetry on the fatigue resistance of alloy AMg, 6N

1990 ◽  
Vol 22 (2) ◽  
pp. 283-289 ◽  
Author(s):  
D. G. Kofto
Keyword(s):  
Fatigue Resistance ◽  
Loading Frequency ◽  
Cycle Asymmetry

Effect of loading frequency, temperature, and cycle asymmetry on the endurance of heat-resistant steels 1Kh2m and Kh18N9. Part 1

1980 ◽  
Vol 12 (4) ◽  
pp. 439-444 ◽  
Author(s):  
V. A. Kuz'menko ◽  
I. I. Ishchenko ◽  
I. A. Troyan ◽  
S. V. Grishakov ◽  
L. E. Matokhnyuk ◽  
...  
Keyword(s):  
Loading Frequency ◽  
Cycle Asymmetry ◽  
Heat Resistant ◽  
Heat Resistant Steels ◽  
Frequency Temperature

scholarly journals CHANGES IN FATIGUE RESISTANCE OF STRUCTURAL STEELS AT DIFFERENT LOADING SPECTRA

2019 ◽  
Vol 62 (10) ◽  
pp. 796-802
Author(s):  
V. V. Myl’nikov ◽  
D. I. Shetulov ◽  
O. B. Kondrashkin ◽  
E. A. Chernyshov ◽  
A. I. Pronin
Keyword(s):  
Fatigue Resistance ◽  
Resistance Index ◽  
Fatigue Curve ◽  
Cyclic Strength ◽  
Structural Steels ◽  
Experimental Results ◽  
Cyclic Behavior ◽  
Material Surface ◽  
Loading Frequency ◽  
Surface Layers

Fatigue strength of widely used engineering structural steels was  studied at various frequencies of loading according to the scheme of  cantilever bending of the rotating cylindrical samples. Fatigue resistance index is tangent of angle of inclination of fatigue curve to axis  of longevity. It is established that 40 and 45 steels belong to the group  of materials in which decrease in frequency of loading leads to cyclic  softening and decrease in fatigue resistance, which is numerically expressed by increasing slope of fatigue curve. Tests of the samples made  of 40X steel had shown that increase in frequency of loading cycles  leads to a noticeable decrease in slope of fatigue curve parameter, i.e.  to an increase in fatigue resistance. Decrease in fatigue resistance parameter is associated with an increase in hardening of material of the  samples (parts) surface layers which reduces fatigue damage to the  surface itself. Dependence of the fatigue curve slope tangent on surface damage at changing loading cycles frequency is shown and it is  stated that, regardless of frequency, damage of material surface layers  increases along the slope of fatigue curve. For each of these groups  mathematical relations are defined. The correlation coefficient providing degree of convergence of experimental results with the constructed fatigue curve was adopted as a criterion of cyclic behavior stability  of steels. It is revealed that increase in behavior stability of 40X steel  is observed with increase in cyclic deformation rate. Tests of 45  steel  have shown that decrease in cyclic strength with increase in loading  frequency does not affect fatigue stability of material. Increased dispersion of experimental results was observed in 40 steel at low loading  frequency, despite the high values of cyclic strength at given loading  frequency. On the basis of conducted experiments, dynamics of behavior of real machine parts and structures subjected to cyclic loads  operating was determined in the studied loading spectrum.

Effect of loading frequency, temperature, and cycle asymmetry on the endurance of heat-resistant steels 1Kh2M and Kh18N9. II

1981 ◽  
Vol 13 (2) ◽  
pp. 163-169
Author(s):  
V. A. Kuz'menko ◽  
I. I. Ishchenko ◽  
I. A. Troyan ◽  
S. V. Grishakov ◽  
L. E. Matokhnyuk ◽  
...  
Keyword(s):  
Loading Frequency ◽  
Cycle Asymmetry ◽  
Heat Resistant ◽  
Heat Resistant Steels ◽  
Frequency Temperature

Effect of loading cycle asymmetry, stress concentration, and fretting corrosion on the fatigue resistance of alloy D16T

1990 ◽  
Vol 22 (5) ◽  
pp. 678-684
Author(s):  
V. I. Dragan ◽  
S. M. Semenyuk ◽  
E. I. Mitchenko ◽  
V. O. Merkulov
Keyword(s):  
Stress Concentration ◽  
Fatigue Resistance ◽  
Fretting Corrosion ◽  
Cycle Asymmetry ◽  
Alloy D16t ◽  
Loading Cycle

scholarly journals Influence of Loading Frequency on Fatigue of Construction Materials

2019 ◽  
Vol 18 (5) ◽  
pp. 427-435
Author(s):  
V. V. Mylnikov
Keyword(s):  
Cyclic Loading ◽  
Fatigue Resistance ◽  
Construction Materials ◽  
Resistance Index ◽  
Fatigue Curve ◽  
Cyclic Strength ◽  
Operating Conditions ◽  
Loading Frequency ◽  
Load Spectrum ◽  
Grain Crushing

Investigations have been carried out in respect of structural steel and titanium alloy fatigue at various cyclic loading frequencies and these investigations have made it possible to reveal regularities in changes of parameters pertaining to fatigue resistance and stability behaviour of the tested materials. A change in cyclic loading frequency affects duration of a single (during one cycle) stay of the material in the loaded state and it has an impact on its durability. In addition, with an increase in frequency of load cycles, deformation rate becomes higher, and stress build-up time is decreasing, while distortion of a crystal lattice is increasing due to reduction of time for development of a weakening process. This process is accompanied by an increase in intensity of grain crushing into fragments and blocks, and their disorientation. Tests on cyclic strength of the studied material samples have been carried out at various frequencies and at a room temperature according to the following loading schemes: cantilever cyclic transverse bending of a flat sample; cantilever bending with rotation of a cylindrical sample; axial tension on a pulsating cycle. Quantitative estimates of a fatigue resistance index in the form of slope tangent in a left branch of the fatigue curve to a cycle axis have been used in order to analyze and evaluate performance and stability of the tested materials. Methods for mathematical statistics have been applied to process the obtained results. Graphic dependences of fatigue curves have been plotted in logarithmic coordinates that allowed to obtain straightening of approximating lines for experimental data. The investigations have revealed that loading frequency has an ambiguous effect on fatigue resistance due to some differences in materials in respect of their reaction to changes in a load spectrum within different areas of the fatigue process, but at the same time it has been found that an increase in fatigue strength leads to a slope decrease in the fatigue curve regardless of a decrease or an increase in a load frequency. The paper proposes a new approach to assess a cyclic strength and durability of materials, and it comprises a system of parameters including a relative coefficient of limited endurance, a correlation coefficient and a slope tangent of the fatigue curve. Behavior dynamics for real machine parts and structures made of these alloys under operating conditions has been indicated in the paper.

Methods and specimens for comparative investigations of fatigue resistance of parts with multilayer surfacing

2019 ◽  
Vol 2019 (2) ◽  
pp. 36-42
Author(s):  
I.A. Ryabtsev ◽  
◽  
V.V. Knysh ◽  
A.A. Babinets ◽  
S.A. Solovej ◽  
...  
Keyword(s):  
Fatigue Resistance
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