Model
Digital Document
Publisher
Florida Atlantic University
Description
High cycle fatigue tests were conducted using symmetrical
center cracked plate specimens in air, sea water and constant
potentials of -1.0V and -1.3V(SCE) at 20 Hz. (1200 cycles per
minute) to determine what effect these environments had on
crack growth rates, delta a/delta n (inches per cycle), of 5086-H34
aluminum when plotted against stress intensity range, delta K (Ksi root of in). Crack growth rates of 10^-8 inches per cycle
were obtained which indicated that apparent threshold stress
intensities, delta K th, exist which are the same for air, sea
water and a constant potential of -1.0V(SCE); however, under
a constant potential of -1.3V(SCE) the threshold shifts to a
significantly higher value. It was also observed that the
different enviroments had a pronounced effect on crack
growth rate only at low stress intensities. Several mechanisms
are considered to explain this behavior.
center cracked plate specimens in air, sea water and constant
potentials of -1.0V and -1.3V(SCE) at 20 Hz. (1200 cycles per
minute) to determine what effect these environments had on
crack growth rates, delta a/delta n (inches per cycle), of 5086-H34
aluminum when plotted against stress intensity range, delta K (Ksi root of in). Crack growth rates of 10^-8 inches per cycle
were obtained which indicated that apparent threshold stress
intensities, delta K th, exist which are the same for air, sea
water and a constant potential of -1.0V(SCE); however, under
a constant potential of -1.3V(SCE) the threshold shifts to a
significantly higher value. It was also observed that the
different enviroments had a pronounced effect on crack
growth rate only at low stress intensities. Several mechanisms
are considered to explain this behavior.
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