Structural Optimization Design And Wheel/Rail Contact Analysis Of Transfer Platform

In locomotive production or overhaul operations,the transfer platform is a commonly used large-scale transfer equipment,mainly used for locomotive transfer operations between different tracks in the workshop.At present,for the most of the structure of the transfer platforms are designed by engineering experience,and has no uniform design specification,the related research mainly focuses on the structural design,statics analysis and electrical control,etc.Therefore,this paper takes a transfer platform as the research object,some key technologies of structure’s dynamic and static performance,structure optimization and wheel rail contact are studied.The main results are as follows:The finite element model of the transfer platform structure is established by ANSYS/LS-DYNA,and the dynamic response of the transfer platform under the action of moving load is calculated and analyzed,than the displacement and stress response of different locomotives and different locomotive speed are discussed.The analysis shows that,when the rated quality locomotive runs at 2m/s speed on the transfer platform,the beam away from the supporting point has larger displacement response,the maximum vertical displacement of the cantilever end of the structure has exceeded the allowable design value;The locomotive traction speed is constant,with the increase of locomotive quality,the vertical displacement of the cross beam increases obviously.When the locomotive quality is fixed,with the increase of locomotive traction speed,the vertical displacement of the cross beam is slightly increased;under moving load,the dynamic stress of the moving platform does not exceed the allowable stress value,and with a certain amount of surplus.On the basis of dynamic response analysis,combined with the current research status of transfer platform structure and《Standard of Crane Design》,the calculation and analysis condition of transfer platform is determined.First,the ANSYS is used to analyze the sensitivity of the design variables of structure,and the parameters of the structural target response are selected to reduce the number of design variables so as to improve the efficiency of optimal design.Then,aiming at the structural characteristics of the transfer platform,the optimization method of the structure supporting position is put forward,and the influence of supporting position change on the overall structural stiffness is discussed.Finally,through the integration of ANSYS and ISIGHT to establish two optimization models,one optimize the structure size only,the other add the structure support position variable.These two mathematical models are optimized and compared.The former’s self-weight is only reduced by 6.39%,while the latter’s self-weight is reduced by 33.72%,significant optimization results have been achieved,the material utilization rate has be greatly improved.The design scheme provides a reference basis for the reasonable formulation and improvement of the structural scheme of the transfer platform.The finite element model of wheel rail contact is established by finite element software ABAQUS,than compared the change of wheel rail contact characteristics in different wheel rail contact factors.The research shows that: with the increase of wheel pressure,the decrease of wheel diameter and the decrease of the curvature radius of the top surface of rail will lead to the increase of wheel rail contact pressure and internal stress and shear stress.The rotation of the wheelset has no obvious effect on the contact characteristics;the increase of yield strength of wheel material will increase contact stress,but it can improve the status of wheel rail plastic deformation.