**2.3 Tensile machine**

In the tensile test, to record the signals emitted from the growth of fatigue cracks in aluminum alloy 2025, we need to grow the initiated cracks in the bending fatigue test by the tensile machine. This device is made by the HIWA company and

*Determining the Characteristics of Acoustic Emission in the Fatigue Crack Growth of Aluminum… DOI: http://dx.doi.org/10.5772/intechopen.99360*

has two jaws to connect the two sides of the specimen and a load cell to measure the tensile force. **Figure 5** shows the schematic of tensile machine. Cracked specimens are attached to both jaws of the machine on both sides, and after determining the tensile speed (1 mm/min in this test), the upper jaw of the machine starts to move upwards at the set speed and the initiated crack begins to grow [8].
