low Cycle fatigue of Fiber Reinforced Concrete Spheres Under External Pressure loading
Harvey Haynes and M. B. Balachandra
Appears on pages(s):
cyclic loads; fatigue (materials); fatigue tests; fiber
reinforced concrete; hydrostatic pressure; static loads.
Nine fiber-reinforced-concrete spheres were subjected to external pressure loading; four spheres were tested to failure by static loading, and five by low-cycle fatigue loading. The state of stress in the wall of the spheres was multiaxial, varying from biaxial on the inside surface to triaxial elsewhere. The average triaxial state of stress was 0 1 = a2 and 0 3 = 0.3 CT . 1 The fatigue data show a substantial difference in behavior compared to that of previous work on confined concrete. Changing the stress levels, c 9 from 0.70 to 0.50 changed the cycles to failure from 10 to 346, respectively. However, a better parameter to describe fatigue behavior was the stress-to-strength ratio, (qcyc/f;' which varied from 1.55 to 1.08, respectively. Under triaxial compression, it appeared that cyclic loading in which all principal stresses cycle was a considerably more severe condition than cyclic loading in which only one principal stress cycles while the other two principal stresses remain constant.