19.4 On the Methods of Physical Mesomechanics and Synergetics
295
strains. Electronic microscopy became the breakthrough that physicists made in
the microcosm of a deformable solid body. During the next half of the century,
plasticity and strength physics was boosted due to studies of occurrence, motion,
and changes of the primary type of structural imperfections—dislocations. It was
hoped that reliable data on structural faults and their migration in a loaded body
will allow making the physical theory of non-elastic deformations at the macrolevel. However, soon this period of hopes turned into the period of disappointments:
efforts to calculate the “stress–strain” curve failed even for uniaxial compression.
There was a need to search for a new, unconventional approach. One such
approach was proposed by V.E. Panin [22, 23], which was later developed into
a new domain of solid state physics—physical mesomechanics. An intermediate
scale is introduced between micro- and macro-levels—mesoscopic. As a result, the
distribution of phenomena accompanying the body loading process looks as follows:
– micro-level: local changes in the crystalline lattice are manifested as the generation of dislocation cores and their displacement in the field of stress gradient;
– meso-level: generation and motion of local zones of non-elastic deformations
as stripes of a mesoscopic scale level within individual aggregates of the internal
structure; it has been experimentally found that linear displacements of these
aggregates are accompanied by their rotation;
– macro-level: generation of a single mains macro-stripe, two parallel macrostripes as a dipole or two conjugate macro-stripes ending in destruction division
of the body into parts.
Local zones of non-elastic strain become concentrators of stresses of various
scales and areas of shift instability, and their motion to an equilibrium state is
considered as a synergetic process. The following [23] synergetic principles of this
process are formulated. 1
Principle 1 A shift in a loaded solid body is related to the local loss of shift stability
and can be done at the micro-, meso-, and macro-scale levels as a local change in
the initial internal structure.
Principle 2 A shift on any scale level can be generated only in the local zone of the
stress concentrator of respective scale since in general the structure of a loaded solid
body preserves its shift stability under the action of the mean applied loading.
Principle 3 The free surface of the body has the least shift stability in the loaded
solid body.
Principle 4 A shift in a continuous medium with a stringent material rotation
generates a zone of flexure–torsion in its way, which is a new stress concentrator.
Principle 5 A shift as a relaxation process in a limited elastic–plastic environment
with specified boundary conditions generates fading elastic and elastic–plastic selfoscillations.
1 Some of these principles coincide in their essence with the axioms formulated in Chap. 17.
295
strains. Electronic microscopy became the breakthrough that physicists made in
the microcosm of a deformable solid body. During the next half of the century,
plasticity and strength physics was boosted due to studies of occurrence, motion,
and changes of the primary type of structural imperfections—dislocations. It was
hoped that reliable data on structural faults and their migration in a loaded body
will allow making the physical theory of non-elastic deformations at the macrolevel. However, soon this period of hopes turned into the period of disappointments:
efforts to calculate the “stress–strain” curve failed even for uniaxial compression.
There was a need to search for a new, unconventional approach. One such
approach was proposed by V.E. Panin [22, 23], which was later developed into
a new domain of solid state physics—physical mesomechanics. An intermediate
scale is introduced between micro- and macro-levels—mesoscopic. As a result, the
distribution of phenomena accompanying the body loading process looks as follows:
– micro-level: local changes in the crystalline lattice are manifested as the generation of dislocation cores and their displacement in the field of stress gradient;
– meso-level: generation and motion of local zones of non-elastic deformations
as stripes of a mesoscopic scale level within individual aggregates of the internal
structure; it has been experimentally found that linear displacements of these
aggregates are accompanied by their rotation;
– macro-level: generation of a single mains macro-stripe, two parallel macrostripes as a dipole or two conjugate macro-stripes ending in destruction division
of the body into parts.
Local zones of non-elastic strain become concentrators of stresses of various
scales and areas of shift instability, and their motion to an equilibrium state is
considered as a synergetic process. The following [23] synergetic principles of this
process are formulated. 1
Principle 1 A shift in a loaded solid body is related to the local loss of shift stability
and can be done at the micro-, meso-, and macro-scale levels as a local change in
the initial internal structure.
Principle 2 A shift on any scale level can be generated only in the local zone of the
stress concentrator of respective scale since in general the structure of a loaded solid
body preserves its shift stability under the action of the mean applied loading.
Principle 3 The free surface of the body has the least shift stability in the loaded
solid body.
Principle 4 A shift in a continuous medium with a stringent material rotation
generates a zone of flexure–torsion in its way, which is a new stress concentrator.
Principle 5 A shift as a relaxation process in a limited elastic–plastic environment
with specified boundary conditions generates fading elastic and elastic–plastic selfoscillations.
1 Some of these principles coincide in their essence with the axioms formulated in Chap. 17.