PSI - Issue 40

L.A. Prokopyev et al. / Procedia Structural Integrity 40 (2022) 365–371 Prokopyev L.A. at al. / Structural Integrity Procedia 00 (2022) 000 – 000

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scheme of low-temperature thermal of a plate specimen is shown in Figure 1, where the dimensions are shown in millimeters.

Fig. 1. Scheme of local low-temperature thermal loading of the flat plate specimen. The temperature field on the plate along the "y" axis is determined from the results of experimental data from thermocouples using the method of least squares. The values of tensile stresses in the direction of the "y" axis for a gradient temperature field are determined as follows: = 2 ∫ ∆ ( ) − (1) The formula for the stress intensity factor in a gradient temperature field takes the following form: = √ 2 ∫ ∆ ( ) − (2) 3. Material and method The basic principles of GOST 25.506-85 (2005) are applied to make a fatigue crack in that there are no guidelines for making a crack in this specimen. Since the crack is fatigued, the fracture mechanics formulas for a sharp crack are used in the calculations. The experiment was carried out using an AE equipment "Expert-2014" manufactured by NPO Alkor, Dzerzhinsk, and according to RD 34.17.444-97 (1998). For the experiment, acoustic