The conventional methods of testing for fatigue cracking resistance (compact samples) are compared with testing with a constant amplitude of the stress intensity factor (DCB samples). Examples are presented of the effect of the ambient environment on the growth rate of a crack in a DCB sample and constant growth rate of a crack in a double beam sample with constant amplitude of the stress intensity factor. The advantages and limitations of the testing methods studied are discussed. It is noted that DCB samples and double-beam samples with crack length independent stress intensity factor hold promise for studying the regularities of crack growth not only under cyclic but also under prolonged static loading.
Gol’tsev et al.