Eventos Anais de eventos
DINAME2019
DINAME2019
Friction coefficient influence on the nonlinear dynamics of a drill-string experimental model with stick-slip
Submission Author:
Bruno Cesar Cayres , RJ
Co-Authors:
Bruno Cesar Cayres, Hans Ingo Weber
Presenter: Bruno Cesar Cayres
doi://10.26678/ABCM.DINAME2019.DIN2019-0128
Abstract
Because of diameter-to-length ratio of the drilling system, torsional vibration mode is present in most drilling processes and may reach an undesired severe stage: stick-slip phenomenon. The stick-slip phenomenon is the main source of component failures during drilling process and may excite other vibration modes. In this work, the nonlinear behavior of an experimental apparatus simulating drill-string in reduced scale is approached. The lumped parameters technique is used to achieve the equations of motion. The nonlinearity rises from the adopted dry friction model which simulates the bit-rock interactions. Numerical and experimental results are compared in order to validate the mathematical model. Subsequently, the local stability analysis is performed using Hurwitz criterion: the equilibrium branches and the torsional map are found. One may observe that the limit points experience Hopf bifurcations. The limit cycles are found numerically. For this, the reference angular velocity is used as bifurcation parameter. Basins of attraction also indicate the coexistence of both stable equilibrium and limit cycle for a range of the bifurcation parameter. The kinetic coefficient of friction is modified and its influence is analyzed.
Keywords
nonlinear analysis, stick-slip phenomenon, drill-string experimental set-up, dry friction-induced vibrations
