路基上双块式无碴轨道道床板疲劳特性影响因素分析

以路基上双块式无碴轨道为研究对象,建立钢筋与混凝土纵向相互作用力学模型、双块式无碴轨道三维有限元静力学模型、列车-双块式无碴轨道垂向耦合动力学模型.根据轴向温度荷载、混凝土收缩荷载、温度梯度荷载及列车荷载作用下道床板混凝土及钢筋应力时程曲线,运用雨流计数法,得到耦合荷载作用下的应力谱.利用Miner线性疲劳累积损伤准则...

Analysis of Influencing Factors on Fatigue Behavior of Double Block Ballastless Track Concrete Layer on Subgrade

Taking double block ballastless track on subgrade as the investigation subject, three mechanical models were established, which inelude longitudinal interaction mechanical model of steel bar and concrete, 3D finite element static model of double block ballastless trackl train-double block ballastless track vertical coupling dynamic model. According to stress time-dependant curve caused by longitudinal temperature, concrete shrinkage, temperature gradient, and train load, the concrete and steel bar stress spectra of track concrete layer were obtained by rain-flow counting method. According to the existing steel bar and concrete S-N curve, A fatigue life prediction model of double block bal- lastless track concrete layer on subgrade was estalished by Miner linear accumulative damage theory. Taking Wuhan-Guangzhou passenger dedicated railway line as an example, some influencing factors on fatigue behavior of double block ballastless track concrete layer on subgrade are analyzed, such as support layer elastic modulus, support layer thickness, track concrete layer thickness, track concrete layer crack spacing, track concrete layer ratio of steel, track concrete layer steel laying mode, concrete construction tempertature and so on.