The Effect of Specimen Thickness Upon the Fatigue Crack Growth Rate of A516-60 Pressure Vessel Steel

1977 ◽  
Vol 99 (2) ◽  
pp. 248-252 ◽  
Author(s):  
A. M. Sullivan ◽  
T. W. Crooker
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Pressure Vessel ◽  
Specimen Thickness ◽  
Pressure Vessel Steel ◽  
Vessel Steel

Fatigue crack growth rate studies on A516-60 pressure vessel steel indicate no effect of specimen thickness in stress-relieved specimens ranging in thickness from 0.25 to 2.0 in. (6.35 to 50.8 mm). A regression curve equation for all thicknesses relating cyclic crack growth rate (da/dN) to crack-tip stress-intensity factor range (ΔK) is obtained. The significance of these results is discussed in the light of current engineering practice and previous studies on size effects in fatigue crack propagation.

Studies on Strain Fatigue Crack Growth Rate Controlled by Displacement or Load of 16MnR Steel

2011 ◽  
Vol 243-249 ◽  
pp. 5680-5685
Author(s):  
Yan Yan ◽  
An Zhong Liu ◽  
Dao Xiang Zhou
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Pressure Vessel Steel ◽  
Vessel Steel ◽  
Plastic Energy ◽  
Weighted Means

In order to understand the strain fatigue crack growth rate of pressure vessel steel controlled by displacement or load, we did experiments on strain fatigue of 16MnR steel and describe the fatigue with the energy method. We have obtained delayed cycle curve of strain fatigue controlled by displacement or load and calculated the J-integral at crack tip. In order to compare strain fatigue crack growth rates of 16MnR steel on two conditions，we compute weighted means of the strain fatigue controlled by displacement or load. Comparing two kinds of fatigue growth rate, it is obvious that the crack growth rate of fatigue controlled by displacement is greater than that controlled by load. All experiments show that compress plastic energy is higher, the fatigue growth rate of 16MnR is lower.

Fatigue Crack Growth in Large Specimens With Various Stress Ratios

1984 ◽  
Vol 106 (3) ◽  
pp. 255-260 ◽  
Author(s):  
F. Ellyin ◽  
H.-P. Li
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Stress Ratio ◽  
Type Equation ◽  
Pressure Vessel Steel ◽  
Vessel Steel ◽  
Stress Ratios

An experimental investigation has been carried out on large plates made of pressure vessel steel A516 Gr.70, to determine the fatigue crack growth rate. The specimen size was 914.4 × 304.8 × 12.7 mm (36 × 12 × 0.5 in.) with an initial central through crack of about 92 mm (3.6 in.). The stress ratio, R, applied to the specimens varied from zero to 0.4. This ratio was maintained constant during a test, but the stress amplitude, Δσ, at times was increased in order to obtain data under a large range of stress intensity factor, ΔK. The crack growth rate, da/dN, is expressed in terms of stress intensities, ΔK and Kmax, through a power-law-type equation. The variation of material constants with the applied stress ratio is discussed. From the data analysis, a general equation for the crack propagation rate is suggested in the form of da/dN = C (Kmax)n where C and n are functions of ΔK, Kmax and material parameters. The results are also compared with the recommended ASME Code formula and are found to be in fairly good agreement.

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