Contact fracture behavior of ice
The formation of an intermediate layer under hydrostatic compression at a shear appearing due to the action of converging and diverging fronts of stress momentums (pulses) is considered. Continuous monitoring of deformational changes in the structure of ice was carried out using acoustic methods. Th...
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| Format: | Article |
| Language: | Russian |
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Nauka
2020-05-01
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| Series: | Лëд и снег |
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| Online Access: | https://ice-snow.igras.ru/jour/article/view/806 |
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| author | V. P. Epifanov |
| author_facet | V. P. Epifanov |
| author_sort | V. P. Epifanov |
| collection | DOAJ |
| description | The formation of an intermediate layer under hydrostatic compression at a shear appearing due to the action of converging and diverging fronts of stress momentums (pulses) is considered. Continuous monitoring of deformational changes in the structure of ice was carried out using acoustic methods. The features of contact ice breaking in the diverging fronts of stress pulses are considered by the example of the slow impact of a rigid spherical indenter on an ice plate simulating half-space. Using the piezoelectric accelerometer, an oscillogram of the impact was recorded and a generalized dependence of the reduced stress on the reduced instantaneous velocity of the impact (semi-cubic parabola) was obtained. It is established that under conditions of the experiment (smooth convex indenter surface and icy half-space) a thin intermediate layer is formed, the properties of which determine the physical similarity in the family of curves «instantaneous force-instantaneous velocity». A rheological model with due regard for the change in the microstructure of ice during the impact is proposed. Quantitative determinations of the deformation changes in structure of solid ice samples were performed under intensive plastic deformation in a matrix with a profile similar to the Laval nozzle. The deformations created by the piston caused forced vibrations in the ice. The working surface of the piston in the form of an ellipsoid together with the smooth walls of the matrix and the reverse cone created conditions for parametric resonance and the formation of fronts of highfrequency stress pulses. Under influence of these pulses, zones with a superplastic fine-crystalline structure of ice (cumulative effect) were formed in ice. In the outlet cylindrical channel, a flow around an obstacle of the ice with the structure of an intermediate layer (dynamic viscosity 20 MPa s) and the distribution of velocities of motion over the channel cross section were studied. The obtained results can be used to simulate the processes of contact destruction of deep rocks by a support or an ice-resistant platform loaded with an ice field. |
| format | Article |
| id | doaj-art-3685299650df4ab9ad8dcbf4d4d2dc2a |
| institution | Kabale University |
| issn | 2076-6734 2412-3765 |
| language | Russian |
| publishDate | 2020-05-01 |
| publisher | Nauka |
| record_format | Article |
| series | Лëд и снег |
| spelling | doaj-art-3685299650df4ab9ad8dcbf4d4d2dc2a2025-08-20T03:59:48ZrusNaukaЛëд и снег2076-67342412-37652020-05-0160227428410.31857/S2076673420020040614Contact fracture behavior of iceV. P. Epifanov0Ishlinsky Institute for Problems in Mechanics, Russian Academy of SciencesThe formation of an intermediate layer under hydrostatic compression at a shear appearing due to the action of converging and diverging fronts of stress momentums (pulses) is considered. Continuous monitoring of deformational changes in the structure of ice was carried out using acoustic methods. The features of contact ice breaking in the diverging fronts of stress pulses are considered by the example of the slow impact of a rigid spherical indenter on an ice plate simulating half-space. Using the piezoelectric accelerometer, an oscillogram of the impact was recorded and a generalized dependence of the reduced stress on the reduced instantaneous velocity of the impact (semi-cubic parabola) was obtained. It is established that under conditions of the experiment (smooth convex indenter surface and icy half-space) a thin intermediate layer is formed, the properties of which determine the physical similarity in the family of curves «instantaneous force-instantaneous velocity». A rheological model with due regard for the change in the microstructure of ice during the impact is proposed. Quantitative determinations of the deformation changes in structure of solid ice samples were performed under intensive plastic deformation in a matrix with a profile similar to the Laval nozzle. The deformations created by the piston caused forced vibrations in the ice. The working surface of the piston in the form of an ellipsoid together with the smooth walls of the matrix and the reverse cone created conditions for parametric resonance and the formation of fronts of highfrequency stress pulses. Under influence of these pulses, zones with a superplastic fine-crystalline structure of ice (cumulative effect) were formed in ice. In the outlet cylindrical channel, a flow around an obstacle of the ice with the structure of an intermediate layer (dynamic viscosity 20 MPa s) and the distribution of velocities of motion over the channel cross section were studied. The obtained results can be used to simulate the processes of contact destruction of deep rocks by a support or an ice-resistant platform loaded with an ice field.https://ice-snow.igras.ru/jour/article/view/806acoustic-mechanical methodcumulative effectintermediate layerplasticitystructure |
| spellingShingle | V. P. Epifanov Contact fracture behavior of ice Лëд и снег acoustic-mechanical method cumulative effect intermediate layer plasticity structure |
| title | Contact fracture behavior of ice |
| title_full | Contact fracture behavior of ice |
| title_fullStr | Contact fracture behavior of ice |
| title_full_unstemmed | Contact fracture behavior of ice |
| title_short | Contact fracture behavior of ice |
| title_sort | contact fracture behavior of ice |
| topic | acoustic-mechanical method cumulative effect intermediate layer plasticity structure |
| url | https://ice-snow.igras.ru/jour/article/view/806 |
| work_keys_str_mv | AT vpepifanov contactfracturebehaviorofice |