Abstract : a mechanical model to analyze the dynamic performance of train and transition section between roadbed and railway bridge was established a nd a series of reasonable criterions were put forward too . based on this , the init ial deformation of rails due to different subsidence of roadbed and bridge abutm ent , the effects of the direction and speed of train on the dynamic performance o f wheel / track system were studied . at last , the method to determinate the length o f transition section was suggested 文摘:建立了列车与路桥过渡段动力特性分析模型,确定了一套轨道过渡段动力特性的评价指标,分析了由基础沉降差引起的钢轨初始变形以及行车方向、行车速度对轮轨系统动力性能的影响,提出了确定路桥过渡段长度的方法。
Applying an exact modal propagation analysis method and self - imaging theory , i analyzed the principle of mmi coupler . then , the self - imaging effect in graded - index waveguide has been analyzed and simulated using three - dimensional bpm . considering normal technology error , a low loss y - branch structure ( symmetric or asymmetric ) with a multimode waveguide transition section is introduced and designed 在设计y分支波导结构时,考虑常规工艺误差的影响,引入多模波导作为y分支波导结构的过渡区,利用参数空间搜索法来设计结构参数,实现低损耗的y分支结构。