Semi‐infinite moving crack in an orthotropic strip sandwiched between two identical half planes

Author(s):  
A. Singh ◽  
S. Das ◽  
H. Altenbach ◽  
E.‐M. Craciun
2020 ◽  
Vol 15 (4) ◽  
pp. 457-470
Author(s):  
Sanatan Jana ◽  
Prasanta Basak ◽  
Subhas Mandal

A cleavage crack can generate plastic deformation in a crystal only if it is moving sufficiently slowly or can be brought to rest. This can be demonstrated very strikingly by the cleavage of rock salt or lithium fluoride crystals at a low rate of loading. The cleavage crack propagates discontinuously under these conditions, and thus provides a range of velocities at which deformation might occur. It is found that intense plastic deformation occurs only in narrow zones around the positions where the crack stops; elsewhere the crack runs freely producing a perfect cleavage. It is possible to detect and at the same time estimate the magnitude of this deformation by studying the interference pattern produced by light reflected from the two surfaces of the crack. Observations of this kind allow the deformation to be interpreted as the production of arrays of loops of dislocation by the slowly moving crack. The interference technique is also valuable for displaying the presence of the crack so that its mode of propagation can be studied. A number of observations of the opening and closing of cracks suggest that a study of this kind using a system of reversed stressing might have an important application to the problems of the propagation of fatigue cracks.


2020 ◽  
Vol 55 (6) ◽  
pp. 885-891
Author(s):  
N. D. Verveiko ◽  
S. E. Krupenko ◽  
A. I. Shashkin

2020 ◽  
Vol 229 ◽  
pp. 106936 ◽  
Author(s):  
Lin Lang ◽  
Zheming Zhu ◽  
Shuai Deng ◽  
Lei Wang ◽  
Chaoyuan Niu ◽  
...  

Author(s):  
Genady P. Cherepanov

By way of introduction, the general invariant integral (GI) based on the energy conservation law is presented, with mention of cosmic, gravitational, mass, elastic, thermal and electromagnetic energy of matter application to demonstrate the approach, including Coulomb's Law generalized for moving electric charges, Newton's Law generalized for coupled gravitational/cosmic field, the new Archimedes’ Law accounting for gravitational and surface energy, and others. Then using this approach the temperature track behind a moving crack is found, and the coupling of elastic and thermal energies is set up in fracturing. For porous materials saturated with a fluid or gas, the notion of binary continuum is used to introduce the corresponding GIs. As applied to the horizontal drilling and fracturing of boreholes, the field of pressure and flow rate as well as the fluid output from both a horizontal borehole and a fracture are derived in the fluid extraction regime. The theory of fracking in shale gas reservoirs is suggested for three basic regimes of the drill mud permeation, with calculating the shape and volume of the local region of the multiply fractured rock in terms of the pressures of rock, drill mud and shale gas.


Meccanica ◽  
2019 ◽  
Vol 54 (6) ◽  
pp. 855-871
Author(s):  
Prasanta Basak ◽  
S. C. Mandal
Keyword(s):  

1987 ◽  
Vol 34 (1) ◽  
pp. 57-64
Author(s):  
H. G. Georgiadis ◽  
G. A. Papadopoulos
Keyword(s):  

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