考虑轮轨黏着变化的货运列车纵向动力学仿真

Simulation for Longitudinal Dynamics of Freight Train Considering Variation of Adhesion

为研究黏着系数对纵向动力学的影响,建立"1+1"型2万吨重载组合列车计算模型,引入剩余黏着力评价机车牵引力的发挥,研究了黏着限制、曲线黏降及曲线润滑因素影响下的黏着系数变化及其可能引发的列车纵向动力学性能差异。结果表明:在直线牵引工况下列车牵引力提升由于黏着限制而变缓慢,所发挥最大牵引力下降,单机车最大牵引力由380 kN限制到272 kN,拉钩力最大值由800 kN减小到595 kN;在R400 m小曲线牵引工况下,牵引力应从第7档位降低到第6档位,确保机车安全通过;考虑曲线润滑时,牵引档位更低:摩擦因数为0.075和0.10时机车降低档位对应为第2,3档位;摩擦因数为0.125时头部和中部机车通过曲线需分别降低到第4,3档位。由于曲线牵引各工况下发挥的最大牵引力相同,拉钩力最大值差异较小。在纵向动力学计算中,列车牵引力利用和黏着系数变化密切相关,轮轨黏着不足将限制机车能发挥的最大牵引力,进而影响车钩力大小。

To research the influence of adhesion coefficient on longitudinal train dynamics,the longitudinal dynamics calculation model for ′1+1′ type 20 000t heavy haul combined train is established in this paper.The residual adhesion force is introduced to evaluate the exertion of locomotive tracting force,and the change of adhesion coefficient under influences of adhesion limit,curve adhesion dropping and curve lubrication is considered to study the difference of longitudinal train dynamic.The results show that,in the case of train tracting on straight track,the maximum tracting force of a locomotive decreases from 380 kN to 272 kN due to the limitation of adhesion,and the maximum coupler-pulling force decreases from 800 kN to 595 kN.When considering curve lubrication on R400 curve,the traction notch must be reduced to the 6th notch from 7th notch to ensure the safety of the locomotive on curve.When curve′s friction coefficients are 0.075 and 0.10,the notch should be reduced to 2nd and 3rd,respectively;when curve′s friction coefficients is 0.125,the notch should be reduced to 4th during leading locomotive′s curve passing,the notch should be reduced to 3rd during middle locomotive′s curve passing.The maximum tracting forces of locomotive are the same.So there is no significant difference in the maximum value of coupler-pulling force.It can be seen that in calculation of longitudinal train dynamics,the exertion of tracting force is closely related to the change of adhesion coefficient,insufficient adhesion between wheel and rail will limit the maximum traction force that the locomotive can exert,and then affect the coupler force.