Аннотация:The goal of this study was to understand how the
roughness of the boundary of two solids surfaces effects their
nonlinear elastic properties and the possible usage of these results
for the solid state surface diagnostic. The investigation of two
media boundary properties was conducted by surface acoustic
waves (SAW), which were excited and received in optically
polished glass padding with angled beam transducers. The
samples with different roughness level were pressed to the glass
padding surface. The influence of external pressure applied to the
boundary between the sample and padding to the nonlinear
acoustic parameter (NAP) value was investigated. The dependence
of NAP from applied pressure was non-monotonic: it raised up
with the pressure increase, passed through the maximum and
lower down with the further pressure increase. At the same time,
the maximum value of nonlinear parameter and the range of
pressure changes was demonstrated by the sample with the
smallest grain size. The effects of Fast Dynamics in samples were
also investigated. The experimental results analysis demonstrated
that the suggested experimental method for studying nonlinear
elastic properties of flat rough boundary with SAW could be
potentially used in nondestructive diagnostics of rough surfaces of
flat solid bodies.