Ge-Row data of deformation localization of raw coal and briquette coal

To compare and analyze the difference in deformation and damage law of
soft and hard porous media materials, the digital image correlation is
used to evaluate the heterogeneous development of strain fields of hard
and brittle raw coal and soft plastic briquette coal materials under
uniaxial compression. Through the defined statistical indexes, the
quantitative characterization of deformation localization is realized, and
the material damage constitutive model based on the statistical indexes of
strain field is established. The results show that the yield stage of raw
coal is not obvious, showing the characteristics of strain hardening and
X-shaped macroscopic shear failure. The yield stage of briquette coal is
more obvious, showing the characteristics of strain softening and a
tensile failure mode. The progress of strain localization can well reflect
the damage and destruction process of materials. The progress of strain
localization of briquette coal can be divided into uniform deformation
stage, localization stage and failure stage, while the stage
characteristics of localized evolution of raw coal is not obvious. The
theoretical results of the damage constitutive model defined by
statistical indexes are in good agreement with the experimental data,
which well reflect the stress and strain characteristics of the two
materials.