Home – Home – Jornals – Russian Geology and Geophysics 2003 number 6

Formation of residual strain in solids was distinguished into a separate problem during studies of spontaneous conversion in a constrained cylinder when it was found out that this form associated with earthquakes, shocks and rock ejecta into mines is not the only species of athermal conversion of elastic strain.
Two more species are the so-called forced volume conversion (FVC) and forced frontal conversion (FFC) manifested, respectively, in plastic flow and in explosive failure of brittle rocks under uniaxial compression on a common press and, presumably, under monotonic hard loading. Forced frontal conversion in metals manifests itself in incremental deformation (stepwise deformation, or Savart-Masson effect, and gearwise deformation, or Portevin-Le Chatelier effect).
Of the four elementary forms of conversion, two volume species (forced volume conversion and thermal conversion) provide monotonic formation of residual strain and two frontal species (forced frontal conversion and spontaneous conversion) cause incremental deformation.
Investigation into the origin and species of residual strain provides additional support for the idea of spontaneous conversion but shows that the SC hypothesis is only one aspect of the problem.
The conversion approach to residual strain can be useful for understanding deformation in rocks and mitigation of related hazard.