体悬电机变轨距转向架动车动力学性能及参数优化

建立了一种适用于1 435/1 000 mm轨距变换、电机体悬的高速动车组变轨距转向架动车的动力学模型；重点计算在2种轨距线路上动车采用不同的轮轨匹配关系、不同磨耗状态下的运行稳定性分岔特性，并计算了轨距、轮轨游间对运行稳定性的影响；计算了车辆运行垂向和横向平稳性以及在不同曲线工况条件下车辆的曲线通过性能，结合相关动力学标准对各项动力学性能指标进行了评定，并对造成各项动力学指标差异的原因进行了简要分析；以电机体悬式变轨距转向架动车的12个悬挂参数为因子，以车辆蛇行失稳速度、轮轴横向力、轮轨垂向力、轮重减载率和脱轨系数5个动力学指标为响应，采用最优拉丁超立方设计方法进行试验设计；建立径向基神经网络代理模型，采用NSGA-Ⅱ多目标遗传算法对动车主要的悬挂参数进行多目标优化。计算结果表明:在设计工况条件下，所设计的高速动车组变轨距转向架动车在2种轨距线路上运行稳定性、平稳性和曲线通过性能均能满足设计要求；在1 000 mm轨距上运行的稳定性优于1 435 mm轨距情况，但运行平稳性和曲线通过性能劣于1 435 mm轨距情况；优化后的悬挂参数可以兼顾车辆的运行稳定性、平稳性和曲线通过性能，使车辆具有更好的动力学性能，在2种轨距线路运行上所有计算性能指标均满足相关标准。 

Dynamics performance and parameter optimization of motor car with body suspension motor variable gauge bogies

A dynamics model of a variable gauge bogie motor car (MC) for body suspension motor high-speed electric multiple units (EMUs), which was suitable for 1 435/1 000 mm gauge changes, was established. The bifurcation characteristics of the running stability of the motor car under different wheel-rail matching relations and different wear conditions were calculated on two gauge lines, and the effects of the track gauge and clearance between the wheel flange and gauge line on running stability were calculated. The vertical and lateral stationarities of the vehicle operation and the curve-passing performance of the vehicle under different curve conditions were calculated. The dynamics performance indexes were evaluated in combination with relevant dynamics standards, and the reasons for the differences in the dynamics indexes were briefly analyzed. Twelve suspension parameters of the variable gauge bogie MC with a body suspension motor were taken as factors, five dynamic indexes, including vehicle hunting instability speed, wheel-axle lateral force, wheel-rail vertical force, wheel load reduction rate, and derailment coefficient, were taken as responses. Moreover, the optimal Latin hypercube design method was used for the experimental design. A radial basis function neural network agent model was established and the main suspension parameters of the vehicle were optimized using the NSGA-Ⅱ multi-objective genetic algorithm. Calculation results show that the running stability, stationarity, and curve passing performance of the designed high-speed EMU variable gauge bogie on two gauge lines meets the design requirements under the design conditions. The running stability on the 1 000 mm gauge is better than that of the 1 435 mm gauge, but the running stationarity and curve passing performance are inferior to those of the 1 435 mm gauge. As the optimized suspension parameters consider the running stability, stationarity, and curve passing performance of the vehicle, the vehicle exhibits a better dynamic performance. All the calculated performance indexes meet the relevant standards in the operation of the two gauge lines. 10 tabs, 13 figs, 31 refs.