Rock drilling activity is continuously increasing when geothermal applications and underground building projects are getting similar volumes than the traditional mining sector. The trend in drilling technology is towards high performance energy-efficient processes. Development of the process requires good understanding of the mechanisms governing the drill penetration for each hit. This paper introduces a single-hit model of the drilling system, which will be later developed to be used in the computer analysis and development of the complete drilling process. The model is based on finite-element description of the parts in the drill rod system including also joint discontinuities. Tool-rock contact is described by a nonlinear path-dependent penetration law including elasticity and fracture phases. The model is used in the analysis of stress wave propagation through the rod system and in the predictions of tool penetration.
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