Application of random process statistics to the rate sensitivity of plane-strain fracture toughness

Correlation functions of random process theory are used to intercompare available fracture toughness (K _Ic) vs loading rate \((\dot K)\) data of three different mild steels. The analyses confirm that large fluctuations in fracture strength are dependent in an extremely sensitive yet statistically reproducible way upon \(\dot K\) , and apparently insensitive to temperature and neutron irradiation. The emergence of a common pattern of rate sensitivityK _Ic \(K_{Ic} (\dot K)\) in these ferritic steels provides a discriminating index of strain rate in the initiation stages of the crack growth process, helpful in aligning fracture models.