Influence of edge Notch geometry with and without presence of ice filling on dynamic behavior of rock.

This study aims to investigate the effects of edge notch characteristics including inclination (0° and 90°), length (0.2-0.6 L), position relative to the incident bar (L/3, L/2, 2 L/3; top/bottom surfaces), and filling condition (dry or ice-filled) on the dynamic response, energy distribution, and fragmentation characteristics of cylindrical iron ore rock specimens under high strain rate loading. Understanding these effects is essential for improving the design of blasting and dynamic loading processes in open-pit mining. Experiments were conducted using a Split Hopkinson Pressure Bar (SHPB) at a constant strain rate of 772.7 s⁻¹. Results show that notch geometry and ice filling significantly affect mechanical properties, energy distribution, and fracture patterns. shorter notch lengths, higher inclinations, increased distances from the incident bar, and ice-filled specimens increased peak strength, elastic modulus, fracture energy, work at peak load, energy consumption efficiency, and fractal dimension. Scanning Electron Microscopy (SEM) observations revealed tensile cracks at lower notch inclinations and shear cracks at higher notch inclinations. Ice-filled specimens exhibited better stress wave transmission and more uniform fragmentation. The X-shaped fracture pattern was mainly observed in dry specimens with 0° notches. Reducing notch length or moving the notch far from the incident bar decreased reflected energy and increased both transmitted and dissipated energies.