PSI - Issue 28

Liudmila Igusheva et al. / Procedia Structural Integrity 28 (2020) 1303–1309 L. Igusheva, Y. Petrov / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 5. Dependence of the threshold amplitude of fracture on the duration of exposure in the presence of the environment, viscoelastic model.

The medium can both have a damping effect on the propagation of waves in the rod and make the structure more strength, and cause the fracture of the rod, increasing the initial impulse. Therefore, the study of strength characteristics and the calculation of stresses and deformations under dynamic loads in rods located in various environments have practical applications. 5. Conclusions In this paper, effects of dynamic deformation and fracture of a rod located in an elastic environment are studied. Deformations and stresses that occur in a rod that performs longitudinal vibrations under dynamic loading are found. The propagation and reflection of waves in a rod of finite length is studied. The influence of the environment on the fracture of the rod is considered, and the possibility of spall fracture is shown. A mathematical model describing these processes is constructed. In the first model, when the rod is considered elastic, the resulting equation of longitudinal vibrations of the rod turns out to be the well – known Klein-Gordon equation. Numerical calculations of deformations occurring in a specific section of the rod are compared with experimental data. The fracture of the rod under dynamic action using a viscoelastic model is studied. It was found that the fracture of the rod can occur both during the direct passage of the wave along the rod, and as a result of spall fracture. The non monotonic dependence of the threshold amplitude of fracture on the duration of exposure in the presence of an environment is revealed, which differs from the results obtained for the classical case in the absence of an environment. Many structures consisting of rods are located in different environments, so the construction of models describing the deformations and stresses that occur in the rods under dynamic loads is of particular interest, both from a scientific and practical point of view. By correctly selecting the materials that make up the rods, and taking into account the influence of the environment in which these rods will experience loads, you can achieve either effective fracture of these rods, or Vice versa, strengthening the structure. Acknowledgements The work was supported by the Russian Foundation for Basic Research (grant 20-01-00291, 18-51-80008). References

Svetlitskiy, V. A., 1987. Mechanics of rods: Proc. for universities. In 2 hours, Part II. Dynamics. M. Higher school, 4–5. Slepyan, L. I., 1972. Non-Stationary elastic waves. L. Sudostroenie, 271–273, 284–285.