Experimental insights and modeling of edge chipping of rocks with button bits

• Edge chipping tests demonstrated the influence of rock strength, bit size, and cutting distance on cutting performance and energy consumption. • Developed models accurately predicted cutting forces, energy requirements, and material removal, supported by experimental validation. • Results offer practical insights for improving excavation efficiency through optimized tool design and operational strategies. Hard rock excavation presents persistent challenges in mining and tunneling due to rapid tool wear, high energy consumption, and limited adaptability of conventional cutting technologies. Recent research emphasizes that promoting tensile fracture, rather than relying solely on compressive or shear failure, can significantly improve cutting efficiency. This study investigates the cutting performance of button bits under tensile-dominated conditions through edge chipping tests, focusing on the effects of bit geometry, rock properties, and cutting conditions on key performance metrics, including peak force, energy consumption, and specific energy. Three rocks with varying mechanical properties—Sanjome andesite, Kimachi sandstone, and Tage tuff—were tested under controlled laboratory conditions. Results indicate that rock strength, bit size, and cutting distance significantly affect cutting performance. Harder rocks, such as Sanjome andesite, exhibited higher resistance to penetration and greater energy consumption, while softer rocks, like Kimachi sandstone and Tage tuff, showed more ductile failure modes. Theoretical models based on contact and fracture mechanics were developed to predict cutting performance metrics. Indentation hardness scaled linearly with bit diameter and rock strength, while strain energy release rate was derived from fracture toughness and Young’s modulus. These parameters, combined with geometric factors, enabled accurate predictions of peak force, energy consumption, chip volume, and specific energy. The models were validated through strong agreement with experimental data. This research highlights the relevance of edge chipping as a method for evaluating tensile-dominated rock fragmentation and offers practical insights into optimizing button bit design and excavation strategies for hard rock environments.