Study on Contact Nonlinear Coupling Vibration Characteristics of Articulated Flexible Drilling Tools
Considering the nonlinear contact between the flexible drill pipe and the guiding screen tube and the effect of rock on the bit,both vibration mechanics and finite element model of the articulated flexi-ble drilling tool were established.In order to verify the feasibility of the finite element model and modal analysis method,adopting the modal analysis method to determine the first three natural frequencies of the external and internal controllable hinged beams was implemented when the hinge reached the rotation limit.Comparing it with the analytical solution shows that,the maximum error is 0.18%only,this verifies the feasibility of both finite element models and modal analysis method.In addition,through the coupled vibra-tion mode analysis of the articulated flexible drilling tool,the coupled vibration mode frequency and vibra-tion mode of the articulated flexible drilling tool were obtained and their dynamic response was analyzed.The results show that,during the normal drilling operation,the flexible drilling tool doesn't cause reso-nance easily,but transverse and torsional coupling vibration may occur to the flexible drill pipe,and the transverse vibration closer to the drill bit becomes more severely.
万方数据
维普
