降伏応力流体の物理（Physics of yield stress fluids）
|対象||教職員向け 大学院生向け 学部生向け|
Amorphous materials such as gels, colloidal suspensions, sands, and foams behave like fluids when the temperature is low or the density is high, but they exhibits a solid-like behavior with finite yield stress at low temperature or high density state. These materials, known as yield stress fluids, have attracted much attention over the last two decades.
The transition to the solid-like states by decreasing temperature is
called the glass transition, while the transition due to increasing
density is known as the jamming transition. In early investigations,
researchers expected a unified concept to understand the two
transitions. Recent studies, however, have revealed the different
origins and critical behaviors between the transitions.
In this talk, recent progress in the studies of yield stress fluids
will be reviewed, where two different theoretical frameworks explain
the appearance of the yield stress. I will also introduce our recent
results on the effect of friction on the solid-like behaviors. The
friction between grains in the yield stress fluids causes a
discontinuous shear thickening: a sudden jump in the stress induced by increasing shear rate, which contrasts the difference of the