Strona 2_redak - Instytut Agrofizyki im. Bohdana Dobrzańskiego ...

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15. SUMMARY
The purpose of the authors of this book was to focus attention of the reader
on what we believe is important for understanding of the mechanical behaviour of
granular materials of biological origin. The main features of agro and food materials
that make them different from mineral materials are strong influence of moisture
content on mechanical behaviour and high deformability of granules. These
differences bring about certain peculiar behaviours and necessity of adjustments of
models of material, experimental techniques and technological solutions.
The material of “Mechanical Properties of Granular Agro-Materials and
Food Powders for Industrial Practice” has been presented in two volumes. Part I
“Characterization of mechanical properties of particulate solids for storage and
handling” concerns mainly issues relevant for these operations, but contains also
considerable amount of related matters. The main theoretical approaches – from
the origins of soil mechanics to micropolar theory and DEM modelling have been
addressed. A review of commonly applied experimental methods and material
parameters has been presented. Finally, a catalogue of material parameters drawn
from laboratory testing of the authors was attached for reference as well as for
comparison with results of other laboratories. The final chapter: “Physical properties
of granular food materials” presents a set of the physical properties of food
powders and granular materials of a wide range of grain size: from cereal grains
to flour and sugar. The catalogue contains following properties of granular solids:
geometrical parameters, the porosity, the bulk density, the coefficient and the
angle of wall friction, the angle of natural repose, the angle of internal friction, the
cohesion, the flow index, the lateral to vertical pressure ratio, the modulus of
elasticity and the Poisson’s ratio. In the case of cereal grains the influence of the
moisture content was considered and in the case of food powders the influence of
the consolidation pressure.
Keywords: granular materials, bulk solids, particulate media grain, seeds,
food powders