**2.1 Aluminum alloy 2025 specimens**

According to the structure determination test, the material of the extracted specimen from the propeller blade was determined as aluminum alloy 2025. Due to the limited dimensions of the propeller blade and the impossibility of extracting the specimen with standard dimensions in the standard reference ASTM-E855–08, the dimensions of the test specimen are selected very close to the standard dimensions [6]. Based on this, the length, width, and thickness of the specimen equal to 160 mm, 30 mm, and 4 mm are selected and specimens with these dimensions are extracted. Also, to initiate a crack, a notch with a thickness of 1.5 mm and 1.25 mm width is created parallel to the width of the specimen and at a distance of 27 mm along the length of the part. This notch helps to increase the speed of crack initiation in the specimen. **Figure 3** shows the aluminum alloy 2025 specimen dimensions.
