Numerical Investigation of PDC Cutter – Rock Interaction using LS-DYNA and Design of Experiment

To be able to predict how a certain process will happen before it happens is the
trend in all the industry, enables one to be prepared for the future. In this line of thinking
the current work is an attempt to simulate the drilling operation to understand the rockcutter
interaction with the aim of optimizing the conditions to reduce the cutting force
process. The Simulation was conducted in LS-DYNA, where the cutter was treated as
rigid tungsten carbide and the rock as sandstone. The rock was stationary, and the cutter
was treated to move at constant speed, with fixed rake angle and cutting depth. Variable
such as cutting speed, bake rake angle, depths of cut and friction coefficient were being
changed in a scientific manner to study the effect of the parameters on the cutting force.
The result showed that LS-DYNA simulate the rock cutting process with accuracy. From
the results the most important factors affecting the cutting force are rake angle and depth
of cut. From examination of the results, the ones that uses the least force have rake angle
of 0 and depth of cut of 0.5mm, the optimum combination of rake angle and depth of cut
would optimize the drilling process. What makes this work unique is the application of
Design of Experiment (DOE) to deeply study how the parameters affect the cutting force
and which parameters affect the process the most.