Performance Prediction For Coupler Separation Based On Multi-Body Dynamics Simulation

The coupler assembly device is a key component of the vehicle connection,and its part geometry is very complicated,there are gaps between the work parts,and the mechanism function is realized by the motion collision.In the actual operation of the vehicle,due to the harsh conditions of the domestic railway route,the force of the coupler parts is complicated.The abnormal separation of the coupler is a major problem that plagues the normal transportation production order.Whether the accidental separation of the coupler can be avoided and whether the dynamic performance of the coupler is stable and reliable is directly related to the safety of railway transportation.The cause of the accident of the coupler separation is complicated,the randomness is strong,the recurrence rate is low,and the observation is poor.It is difficult to study the cause of the accident through field test.And at present,there is no mature theory,technology and method to support the prediction of the dynamic performance of the coupler,and it is impossible to predict the random impact of the outside when the coupler is abnormally unlocked.In the multi-body dynamics simulation platform RecurDyn,this paper uses multi-body dynamics theory and technology to silulate the actual running state of the coupler and solve the kinematics and dynamic parameters of the coupler under different random impact conditions.And this paper will acheives the prediction of the impact acceleration of the accidental separation of the coupler.Firstly,combined with the structure and working characteristics of the coupler parts,the RecurDyn multi-body dynamics simulation software was selected and the 3D model was constructed in the simulation software.The new multi-body dynamics problem of the coupler device is solved and calculated by using the new motion equation theory and the complete recursive algorithm in the software.The working state of the actual operation of the coupler device is reproduced,and the reliability of the model is verified.Secondly,the random impact that the vehicle is subjected to during actual operation is defined as the instantaneous acceleration,and the simulation experiment plan is designed.The random impact of the coupler is a compound motion of translation,vibration and oscillation.This thesis explores the effects of three basic motion forms of translation,vibration and swing on the reliability of coupler separation.The translation scheme of the coupler is divided into three types:longitudinal,vertical and the coupled motion forms.The vibration scheme of the coupler is divided into a single longitudinal vibration and a separate vertical vibration.Since the head shaking of the vehicle has little influence on the dynalic reliability of the coupler in the actual operation of the vehicle,the swing of the coupler is only a nodding simulation scheme.Finally,based on the collision contact modeling technology in the multi-body dynamics software platform RecurDyn,the simulation experiment of the random impact condition of the coupler is carried out,which reproduces the working state of the coupler device in actual operation;analyzed the longitudinal and vertical acceleration of random impact required by the coupler to reach the unlock position.The algorithm of SVM(Support Vector Machine)is used to solve the acceleration boundary of the unlocking area of the coupler and the safety zone,so as to predict the dynamic reliability working range of the coupler.The simulation results show that the vertical acceleration impact is a sensitive factor for the separation of the coupler.The boundary line shows that at the present stage if the longitudinal impact of the longitudinal impact is less than 3g and the vertical impact is less than 0.7g during the actual operation of the vehicle,the dynamic anti-creep performance of the coupler is reliable,and the coupler will not be separated.In this paper,the multi-body dynamics simulation technology combined with SVM is used to predict the unlocking area of the coupler,which provides a theoretical reference for the design and application of the coupler to judge the dynamic reliability of the coupler.It can avoid the occurrence of accidental separation of the coupler and can effectively improve the vehicle operation safety.