Cyclic AE count rate and crack growth rate under low cycle fatigue fracture loading

Abstract In the low cycle fatigue fracture testing with KS (or JIS) SS41 steel, crack growth rate, AE count rate and J- integral range are measured to get empirical relationships between crack growth rate and J- integral range, AE count rate and J- integral range as well as AE count rate and crack growth rate. All the relationships are shown to be linear on the log—log graphs. It is also shown that the linear relationships can be formulated by using Dunegan's assumption and elastic-plastic fracture mechanics along with the well-known relationships of crack growth rate and J- integral range. It is concluded that the differences between experimental and theoretical values are due to the problem of Dunegan's assumption.