Study of Growth of Fatigue Cracks in Metallic Samples Using Methods of Acoustic Emission and Strain Measurement

Results of cyclic stress tests of planar samples from the D16T duralumin 2 and 6 mm thick performed with the help of the methods of acoustic emission (AE) and strain measurements are reported. The variables recorded in the tests were the applied load, number of loading cycles, length of a fatigue crack, strain in sample material, and parameters of AE signals. In addition, in tests of samples 3 mm thick the stress intensity factor was maintained constant as fatigue cracks grew over fixed intervals of lengths, and information was derived from total counts of AE pulses, their energy distributions and spectral characteristics.