Nonlinear dynamics of a drill-string with uncertain model of the bit-rock interaction

T.G. Ritto , Christian Soize , R. Sampaio

The drill-string dynamics is difficult to predict due to the nonlinearities and uncertainties involved in the problem. In this paper a stochastic computational model is proposed to model uncertainties in the bit-rock interaction model. To do so, a new strategy that uses the nonparametric probabilistic approach is developed to take into account model uncertainties in the bit-rock nonlinear interaction model. The mean model considers the main forces applied to the column such as the bit-rock interaction, the fluid-structure interaction and the impact forces. The nonlinear Timoshenko beam theory is used and the nonlinear dynamical equations are discretized by means of the finite element method.

Mots clés: Drill-string dynamics; Bit-rock probabilistic model; Nonlinear stochastic dynamics; Nonparametric probabilistic approach

T.G. Ritto, Christian Soize, R. Sampaio. Nonlinear dynamics of a drill-string with uncertain model of the bit-rock interaction. International Journal of Non-Linear Mechanics, 2009, 44 (8), pp.865. ⟨10.1016/j.ijnonlinmec.2009.06.003⟩. ⟨hal-00564078⟩