动车组转向架构架结构型式评价方法

Structural Pattern Evaluation Method for EMU Bogie Frames

转向架构架是动车组走行部主要承载部件,疲劳强度与轻量化是结构设计的核心内容。以国内主型动车组箱梁型和管梁型构架进行对比研究,通过刚柔耦合车辆动力学仿真及应变寿命疲劳损伤计算,比较轨道三角坑冲击、高速直线运行和低速曲线通过三种典型车辆运行状态下的构架模态振动响应、应变能及疲劳损伤量。根据构架的承载类型,计算构架弹性变形的模态贡献量及对应的应变能分量,提出了应变能质量比作为材料综合利用率的评价方法,用以量化结构的抗疲劳和轻量化设计水平。采用该指标系统评价了两种构架的结构型式:箱梁型构架的垂向刚度低于管梁型构架,垂向弯曲变形量较大的区域如侧梁底部其静态应变能质量比高于管梁型构架;箱梁型构架扭转刚度高于管梁型构架,扭转变形较大的区域如横梁与侧梁的连接位置其动态应变能质量比要小于管梁型构架。提出合理优化质量分布以提高构架主载荷模态频率、降低应变能质量比为目标的结构设计与评价方法。

Bogie frame is a major loaded part of EMU running gear. Fatigue strength and lightweight are kernel objects in frame structure design. Comparison studies on box type and tube type bogie frames is taken through rigid-flexible coupling vehicle dynamic simulations and strain life fatigue damage computations. Modal vibration responses, total strain energy and fatigue damages are obtained under track twist, high speed straight line and S curving operation conditions. According to the loading types, modal participant coefficients and respected strain energy fractions are compared for the two types of bogie frames. Strain energy mass ratio is proposed to evaluate material usage. Structural patterns of two type bogie frames are systemically evaluated by strain energy mass ratio and modal frequency index within the framework of fatigue strength.