Analysis Of Locomotive Wheels Based On S-669 Standard

For the sake of speeding up the development of autonomous high speed train wheels,and better verifying whether the new design of the wheels can meet the requirements,we China needs to have autonomous wheel standard assessment procedures.The current AAR S-660 standard has some limitations while assessing wheels,only by assessing the effect of the elastic contact stress on the wheel disk under the limiting load to verify whether the wheel can meet the strength requirements.The standard does not take into account the impact of the heat treatment process on the wheel performance during the wheel production process,nor does it take into account the effects of the interference fit of the axle and the wheel to the radial stress.The latest version of the Accociation of American Railroads S-669 standard takes into account the effects of heat treatment and the interference fit of the axle and the wheel to the radial stress,and carries out the elastic contact stress analysis and the standard is suitable for assessing the newly designed wheels.So far,the analysis of axle interference fit and the study of wheel-rail contact in China did not take into account the effect of residual stress on heat treatment.Bases on the AAR S-669 standard,this article analyses the residual stress of a 36-inch wheel on residual stress,adds the influence of residual stress to the analysis of the interference fit and wheel-rail contact,and the result is closer to the actual situation.Firstly,this paper analyses the effect of the temperature field of the heat treatment on the internal stress of the wheel,and respectively calculates the residual stress of the heat treatment of the old and the new wheels.Next,this paper carries out the interference fit analysis of the axle and the wheel,respectively carries out the the interference fit analysis with no residual stress and the interference fit analysis which superimposes the residual stress.Then,this paper compares the analysis results.After that,this paper respectively carries out the wheel-rail contact stress analysis based on S-660 and S-669 standards.By comparing the analysis results,this paper comes to a conclusion that the selected wheel meets the strength requirements of S-669 standard.At last,this paper assesses the reliability of the wheel and lays the foundation for assessing the fatigue strength of the wheel.This study finds that,in addition to the selected wheels meet the standard strength requirements,the maximum residual stress of the old wheel is higher than that of the new wheel,but the depth of the compressive stress is less than the new wheel.Heat treatment residual stress has a direct impact on the stress of the interference fit of the wheel and axle.The interference fit also affects the residual stress at the rim,but has little effect on the depth of the residual stress.The braking heat has a great influence on the equivalent stress of the radial.The wheel's mechanical properties which experienced heat treatment have changed a lot.