Volume 1, Issue 5 (September 1973)
The Effect of the Intermediate Principal Stress on Triaxial Fatigue of 7075-T6 Aluminum Alloy
Fatigue tests of 7075-T6 aluminum alloy under synchronous pulsating triaxial stresses were performed with three different values of the intermediate principal stress. Thick-walled tubes were subjected to internal pressure plus axial stress such that the state of stress at the inner surface was as follows: in the first case, the intermediate principal stress was a compression equal to the internal pressure; in the second, it was a tension equal to the internal pressure; and in the third, it was a tension equal to the hoop stress at the inner surface. Results showed no effect of the intermediate principal stress.