A FRACTURE STATISTICS ESTIMATE OF THE FATIGUE LIMIT OF A BOROSILICATEGLASS

The fatigue limit of a borosilicate glass was experimentally determine d by imposing a series of holding-stresses at intermediate stress leve ls during conventional direct-to-failure strength tests. This techniqu e results in a distinct change in the low strength, large flaw size po rtion of the strength distribution of the survivors. The break-point f or this change in the strength distribution was used to estimate the r oom temperature fatigue or stress corrosion limit (K-IO) of the glass in distilled water. A K-IO of 0.21 M Pa m(1/2) was estimated and is co mpared with other estimates of the fatigue limit in other and similar glasses.