Colloquia

Summary

This thesis compares the effectiveness of dual reciprocating drilling and conventional rotary drilling, with a focus on the advantages of bio-inspired drilling technologies. Using experimental data and numerical simulations through the Discrete Element Method (DEM), it analyzes the performance of these drilling techniques under various conditions and identifies key factors influencing their effectiveness. The research aims to fill a gap in understanding the mechanical behaviors of different drilling mechanisms and assess the industrial potential of reciprocating drilling.

Initial penetrative and rotary drilling experiments confirmed that rotational drilling reduces normal force, while moisture significantly increases it. However, due to limitations, dual reciprocating drilling experiments were not fully conducted, so the model was validated only for rotational and penetration drilling, showing less than 15% discrepancy between experimental and simulated data. The model was scaled to study the effects of friction, particle size, and speed on drilling forces, highlighting the complex behavior of granular substrates.

A major innovation in the study is the development of a model that simulates dual reciprocating motion, allowing comparison of normal forces generated by penetrative, rotational, and reciprocating drilling methods. Results indicate that reciprocating drilling generally reduces normal force compared to rotational drilling, especially when operated at an optimal frequency range of 25-35 Hz. Outside this range, the advantages diminish, emphasizing the importance of operational parameters in maximizing performance.

Despite lower normal forces, the study stresses that normal force alone does not define drilling performance. Factors like material removal rates, tool wear, and failure modes need further investigation to fully assess the benefits of reciprocating drilling. The research lays a strong foundation for the development of bio-inspired drilling technologies, which could significantly improve drilling efficiency, reduce tool wear, and minimize environmental impact. Future work should focus on refining these technologies and exploring their applications in industries like oil and gas, construction, and geotechnical engineering.

In conclusion, this thesis enhances the understanding of reciprocating drilling mechanisms and highlights their potential to transform drilling practices by improving efficiency, precision, and sustainability. The findings open the door for further exploration of bio-inspired drilling methods, aiming for their optimization in industrial applications.