The effect of narrow-band random loading on the high cycle fatigue strenght of edge-cracked mild steel plates

1979 ◽  
Vol 1 (1) ◽  
pp. 17-22 ◽  
Author(s):  
L POOK ◽  
A GREENAN
Keyword(s):  
Mild Steel ◽  
High Cycle Fatigue ◽  
Narrow Band ◽  
Steel Plates ◽  
Cycle Fatigue ◽  
Random Loading

Exploratory Tests on the Effects of Random Loading and Corrosive Environment on the Fatigue Strength of Fillet-Welded Lap Joints

1975 ◽  
Vol 17 (4) ◽  
pp. 181-185 ◽  
Author(s):  
K. J. Marsh ◽  
T. Martin ◽  
J. McGregor
Keyword(s):  
Fatigue Strength ◽  
Mild Steel ◽  
Narrow Band ◽  
Fatigue Tests ◽  
Lap Joints ◽  
Corrosive Environment ◽  
Test Frequency ◽  
Constant Amplitude ◽  
Random Loading ◽  
Loading Tests

Fatigue tests on simple, fillet-welded, mild steel lap joints have been carried out to determine the effects of a corrosive environment and random loading. At normal testing frequencies, a brine-drip environment had no effect on the constant-amplitude fatigue strength at short endurances. At stresses less than the in-air fatigue limit, the corrosive environment was sufficient to allow crack growth at very low stress levels. In these corrosive environment tests, reducing the test frequency by a factor of 50 halved the life. The results of narrow-band random loading tests could be predicted reasonably accurately either by a fracture mechanics method or by Miner's rule.

Cumulative Damage in Push-Pull Fatigue of Fillet-Welded Mild Steel Plate Subjected to Narrow Band Random Loading

1970 ◽  
Vol 185 (1) ◽  
pp. 339-351 ◽  
Author(s):  
D. J. White ◽  
J. Lewszuk
Keyword(s):  
Mild Steel ◽  
Steel Plate ◽  
Narrow Band ◽  
Fatigue Tests ◽  
Cumulative Damage ◽  
Mean Stress ◽  
Constant Amplitude ◽  
Random Loading ◽  
The Relationship ◽  
Made In

Push-pull fatigue tests have been made in constant amplitude loading and in narrow band random loading on fillet-welded cruciforms made from 3/8 in thick mild steel plate to B.S. 1501-151 Grade 28. The test frequency was 250 Hz, mean tensile stresses of 0, 5 and 10 tonf/in2were employed and tests were extended for endurances of up to 108cycles. Curves have been fitted to the S-N results using the relationship N( S — So)α= C and on the assumption that this may be extrapolated beyond 108cycles, curves showing the effect of mean stress are given for both constant amplitude loading and narrow band random loading for endurances up to 1012cycles. Suitable factors of safety should be applied to these stresses before use in design. For endurances beyond 107cycles, an increase in tensile mean stress from 0 to 10 tonf/in2reduced the fatigue strength by about 50 per cent in both constant amplitude loading and random loading. Reasonable agreement was found at all mean stresses between the experimental random loading S-N curves and those predicted using the constant amplitude results and the Palmgren-Miner cumulative damage hypothesis.

A Procedure for Fast Evaluation of High-Cycle Fatigue Under Multiaxial Random Loading

2001 ◽  
Author(s):  
Bin Li ◽  
Manuel de Freitas
Keyword(s):  
Shear Stress ◽  
Fatigue Damage ◽  
High Cycle Fatigue ◽  
Stress Amplitude ◽  
Hydrostatic Stress ◽  
Evaluation Procedure ◽  
Cycle Fatigue ◽  
Random Loading ◽  
Proportional Loading ◽  
Fast Evaluation

Abstract This paper presents a fast evaluation procedure for high-cycle fatigue (HCF) under multiaxial random loading. The recent multiaxial cycle counting method of Wang and Brown is used to identify the loading reversals. For each identified reversal, the effective shear stress amplitude is directly calculated from the component stress ranges by an equation derived from the MCE approach, which is a newly developed method to account for non-proportional loading effect. This shear stress amplitude and the maximum hydrostatic stress during the time period of an identified reversal are used to evaluate the fatigue damage for that reversal by Crossland’s criterion. The fatigue damage of the loading block is then calculated by summing the damages of all the identified reversals by Miner’s rule. Comparisons with other multiaxial HCF approaches show that the procedure is a computationally efficient and conservative engineering approach.

Crack Arresting With Crack Deflecting Holes in Steel Plates

2020 ◽  
Author(s):  
Mostafa Atteya ◽  
Ove Mikkelsen ◽  
Dimitrios G. Pavlou ◽  
Gerhard Ersdal
Keyword(s):  
Crack Propagation ◽  
Experimental Work ◽  
High Cycle Fatigue ◽  
Experimental Studies ◽  
Propagation Direction ◽  
Steel Plates ◽  
Cycle Fatigue ◽  
Numerical Studies ◽  
Crack Propagation Direction ◽  
Good Agreement

Abstract Experimental and numerical studies of the effect of crack deflecting holes in steel plates under high cycle fatigue are presented in this paper. The experimental studies show that with the careful location of the holes, crack propagation can be arrested. A numerical model is provided and validated against the experimental work. The numerically predicted crack propagation direction and crack growth rate were in good agreement with the crack propagation obtained in the experimental work.

A Procedure for Fast Evaluation of High-Cycle Fatigue Under Multiaxial Random Loading

2002 ◽  
Vol 124 (3) ◽  
pp. 558-563 ◽  
Author(s):  
Bin Li ◽  
Manuel de Freitas
Keyword(s):  
Shear Stress ◽  
Fatigue Damage ◽  
High Cycle Fatigue ◽  
Stress Amplitude ◽  
Hydrostatic Stress ◽  
Evaluation Procedure ◽  
Cycle Fatigue ◽  
Computationally Efficient ◽  
Random Loading ◽  
Fast Evaluation

This paper presents a fast evaluation procedure for high-cycle fatigue (HCF) under multiaxial random loading. The recent multiaxial cycle counting method of Wang and Brown is used to identify the loading reversals. For each identified reversal, the effective shear stress amplitude is directly calculated from the component stress ranges by an equation derived from the MCE approach, which is a newly developed method to account for nonproportional loading effect. This shear stress amplitude and the maximum hydrostatic stress during the time period of an identified reversal are used to evaluate the fatigue damage for that reversal by Crossland’s criterion. The fatigue damage of the loading block is then calculated by summing the damages of all the identified reversals by Miner’s rule. Comparisons with other multiaxial HCF approaches show that the procedure is a computationally efficient and conservative engineering approach.

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