Work

Numerical Simulation of Rock-Breaking Mechanism by Spherical Tooth Impact in Granite Formation

Year: 2025

Type: article

Abstract: With the increasing depth of mining operations and the emergence of complex geological conditions, pneumatic down-the-hole (DTH) hammers have become an efficient drilling technology. This method utilizes high-pressure air to drive hammering actions for rock fragmentation. However, the layout and durability of tungsten carbide buttons significantly affect the rate of penetration (ROP). This study focuses on optimizing the button arrangement for large-diameter reverse circulation pneumatic DTH hammers to improve drilling efficiency. A numerical model incorporating zero-thickness cohesive elements was developed to simulate rock fracturing. A comparative analysis of 16 mm and 22 mm buttons under varying drilling pressures (1–1.8 kN) and impact energies (20–40 J) was conducted. Key metrics, including penetration depth, fragmentation range, stress-affected zone, and specific energy consumption, were analyzed. The results indicate that 22 mm buttons under 35 J impact energy and 1.4 kN drilling pressure exhibit superior performance, with optimal circumferential (47.2 mm) and radial (51.2 mm) spacing determined through stress superposition analysis. This configuration enhances the weakened rock strength zone, providing critical guidance for DTH hammer design.

Source: Applied Sciences

DOI: 10.3390/app15073649

Authors: Jing Zhou, Kunkun Li, Hao Wu, Yuan Dong, Bairu Xia

Institutions: China University of Geosciences (Beijing), China National Administration of Coal Geology

Language: English

Topic: Tunneling and Rock Mechanics

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $2,896