First, the disk and
parallel bond moduli and the ratios of normal to shear stiffness were set equal between the disks and
parallel bonds to reduce the number of independent parameters [22].
Therefore, it is feasible to script Fish languages to monitor the broken number of
parallel bonds in real time, thereby researching and analyzing damage evolution and acoustic emission properties of rocks.
In this model, the particle is similar to fine sand, and the
parallel bonds among particles are similar to cement.
At these contacts, the
parallel bonds are removed and the smooth joints are defined in a direction parallel with the joint plane.
When the compression of the coal-rock specimen was simulated with PFC, the program based on Fish language was used to monitor the number of fractured
parallel bonds at each moment (each step).
The energy stored in
parallel bonds is closely related to the generation and propagation of cracks.
During the particle movement under the external loading, a great number of
parallel bonds were subjected to compressive stress, but some
parallel bonds may be subjected to tensile stress.
Once the SJ model is created, preexisting
parallel bonds would be deleted and replaced with SJ model.
Fourthly, the
parallel bonds were installed throughout the assembly between all particles that were in near proximity to finalize the specimen.
Thus,
parallel bonds that are capable of resisting shear, tension, and moment were installed between particles.
The assembly of balls is arranged regularly and tightly within a specified region, and contact and
parallel bonds are used to meet the assumption.
It has two different bond models--contact bond model (CBM) and
parallel bond model (PBM)--generally used for simulating granular materials and compact materials, respectively.