New drilling techniques have been studied to increase the penetration in hard rock. These techniques use harmonic load and. in some cases, also impacts to generate a greater penetration rate. Analyzing only a percussive penetration phenomenon, the new model presented in this paper allows the forward motion (with a drift) in stick-slip condition without impact. Numerical arid experimental investigations are presented and are qualitatively compared. Expanding the numerical analysis it is shown that the behavior may vary from periodic to chaotic motion.
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