PSI - Issue 79

Oleg Plekhov et al. / Procedia Structural Integrity 79 (2026) 168–175

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of several times. Conversely, in gigacycle fatigue tests, LSP reduced the fatigue limit by three orders of magnitude due to significant internal tensile residual stresses generated within the specimen volume. 2. Experimental setup To carry out LSP experiments, I СММ UrB RAS (Perm, Russia) developed a custom experimental setup (Fig. 1).

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Fig. 1. (a) LSP setup "ICMM UrO RAS" (Perm, Russia) Nd:YAG laser Beamtech SGR-Extra-10; (b) four removable optical systems; (c) robotic six-axis manipulator STEP SR50.

The system includes a Nd:YAG laser (Beamtech SGR-Extra-10) and a six-axis robotic manipulator STEP SR50. The laser operates at a wavelength of 1064 nm with a maximum pulse frequency of 5 Hz. Pulse energy is adjustable from 1 to 9 J, and the pulse duration is fixed at 10 ns. To quantify the pressure impulse, a photonic Doppler velocimeter (PDV) was assembled. The experimental setup and principal scheme of the PDV experiment are presented in figure 2. The PDV includes the following components: laser with wavelength 1550 nm; oscilloscope with a bandwidth of 2 GHz, 4 analogy channels; four InGaAs-based photodetectors; acoustic-optical modulator (AOM). The apparatus enables the measurement of the velocity of a specimen (construction part) free surface with high precision, up to 2 m/s in range from 5 m/s to 1380 m/s.

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Fig. 2. (a) Photonic Doppler velocimetry; (b) and schematic diagram of PDV (c) and experiment.