Digital image processing (DIP) based fragment
analysis
Digital image processing method has an accuracy of measuring
~50 micrometer based on watershed segmentation algorithm and
deep
learning techniques.
This code will be helpful for better understanding the
fragment size distribution at micro scale for impact tests.
Blast master is available with an
user-fridendly interface now
The blast module deploys some common explosive materials and
the detonation process can be reproduced. We are adding the
effect of gas penetration in this module and more details
will be coming soon.
Strain rate mechanism standing on the
microcracking and fragmentation
The strain rate mechanism can be attributed to inertial
force, fracturing transition at micro scale and dynamic
pulverization. The role of transgrannular fracturing acted
in dynamic fracturing of rocks is regarded as the main
underlying reason
controls the enhancement in peak strength, as well as other
macro behaviours.
Blast fracturing in association with and
without DFN
The preexisting DFNs will significantly influence the
fracturing pattern of blasts, more joints are activated
due to the multiple reflection on the discontinuities.
Review on the crack initiation and crack
damage stresses of rocks
In this work, we reviewed the crack characteristic stresses
of different rock types,
and built the relation between the crack initiation and
crack damage stresses as a function of the peak strength of
rocks.
There are two types of typical failure modes for dynamic
compression test. The class I is controlled by the extra
energy and strain recovery is found in the post-peak. The
class II is a result of high strain rate impacts,
which causes pulverization and huge energy cost.
Fragment model and mean fragment size on
strain rate
We proposed a new kind of fragment theory model based on the
energy conservation for brittle materials under dynamic
compression. The state of initial defects will be rather
important
to determine the mean fragment size comparing to Grady
model.
The full stress-strain curve can be divided into initial
loading, constant stress rate, peak stress, crack
coalescence, rapid unloading and ultimate failure.
Predict the mechanical properties of rock from
its mineralogy
In this study, a multiscale grain-based
continuum–discontinuum method is proposed to investigate the
fracturing process for heterogeneous rocks and the
microscopic mechanisms of crack initiation and propagation
from the aspects of petrography, mineralogy and
microstructures. The material heterogeneity is realistically
reproduced from a high-resolution image-based technique and
the microstructures of granitic rocks are explicitly
modelled by introducing the multiscale grain model.
