  Recent progress in nanotechnology enables us to utilize the elastic strain
engineering, the emerging technology capable of controlling the physio-chemical
properties of materials via externally-imposed elastic strains, for hard
materials. Because the range of accessible properties by imposing elastic
strains are set by materials' elasticity limits, it is of great importance to
suppress the occurrence of any inelastic deformations and failure, and thereby
the fundamental knowledge on fracture behavior at nanoscale is highly required.
The conventional Weibull theory, which has been widely used for last a few
decades to explain the failure statistics of brittle bulk materials, has a
limitation to be directly applied to the samples of nanometer dimensions
because the baseline assumption on statistical equivalence becomes intractable
for small samples. In this study, we suggest an integrated equation presenting
the sample size effect on fracture strength for brittle nanomaterials by
further considering the confinement of the flaw size distribution. This new
approach is applicable to any homogeneous brittle nanomaterials whose failure
is governed by linear elastic fracture mechanics, and shows good agreement with
experimental data collected from literatures. We expect that this theoretical
study offers new guideline to employ brittle nanomaterials in designing and
fabricating the advanced strain engineering system.
