Probability Reliability Analysis And Parameter Optimization Of Mud Pump Power End Based On Finite Element Method

Mud pump is an important part of drilling equipment,which is widely used in oil drilling industry.With the emergence of deep wells and ultra-deep wells,the demand for high-power and high-pressure mud pumps has become increasingly large.However,as the working condition of the high-power mud pump in the severe working platform is becoming worse,problems about the reliability of the mud pump and the rationality of the structure need to be solved urgently.The power of the mud pump is driven by the crank link mechanism,and the reliability of the work and the rationality of the size parameters determine the reliability of the whole mud pump work and the volume or weight of the mud pump as a whole.In this paper,besides ensuring the mechanical properties of mud pump power end at the same time implementing the probabilistic finite element reliability analysis and parameter optimization are also carried out to realize the demand of the market for high pressure and high power mud pump.The main research contents are as follows:1)According to the working principle of the mud pump,the power end of the mud pump is simplified as a crank connecting rod model.The kinematic characteristics of the dynamic end are analyzed by using the theory of plane motion of rigid body,and the force analysis of the crank connecting rod mechanism is also carried out through that way.The kinematic curves and the force curves of the components in the model are obtained by MATLAB.2)The three-dimensional model of the mud pump power end is established by using the 3D solid modeling software Pro/E,and is imported into the finite element analysis software ANSYS.Based on the force analysis of the power end,the static finite element analysis is carried out to obtain the stress of each analysis object under the most severe working conditions.3)Considering that part of the power end is flexible body,the modal analysis and flexibility of the flexible body is carried out through ANSYS and then put into the assembled ADAMS to rigid-flexible coupling dynamics simulation,thus obtaining the dynamic stress of the flexible body.4)The finite element reliability analysis of the connecting rod with material,size and load randomness is carried out based on the probabilistic design solver of the finite element software ANSYS as to obtain the reliability of the connecting rod which isunder work.The reliability of connecting rod is 0.9765.5)According to the result of probabilistic finite element reliability analysis of connecting rod and the irrationality of connecting rod size,and the size parameter is optimized with size parameter used as the design variable,maximum stress used as the state variable and minimal volume used as the objective function,and the optimized volume is reduced by 420 cubic millimeters and its stress is decreased by 4.93 MPa.