基于离散元与有限元耦合的有砟道床沉降特性研究

Research on Settlement Characteristics of Ballasted Ballast Based on Discrete Element and Finite Element Coupling

随着铁路技术向高速重载方向的发展,对有砟铁路的研究意义愈加重大。文中针对稳定作用下轨枕沉降和轨枕下方道砟颗粒运动情况之间的联系进行了分析。采用有限元与离散元耦合的方法对轨枕沉降量和道床沉降进行研究。利用有限元软件建立500 mm×230 mm×160 mm简化缩小比8∶1的轨枕长方体模型,然后对轨枕的单元节点进行提取。通过离散元软件EDEM的API接口实现对节点坐标的离散元替换构造出轨枕离散元模型,并利用球形颗粒拼接出不同形状道砟颗粒,完成轨枕-道床离散元模型建立在离散元软件中构建出轨枕-道床缩小模型。同时搭建与轨枕模型同尺寸的试验模型,通过对比验证确定构建的轨枕-道床模型的有效性与可靠性。对不同激振频率下轨枕与道床沉降量分析,得到轨枕沉降规律,确定在稳定过程激振频率达到36 Hz时轨枕沉降量达到最大值。文中得到轨枕沉降量与稳定作业时间的关系,即随着稳定过程的进行,道床沉降量增大,轨枕正下方区域沉降效果明显。

With the development of railway technology in the direction of high-speed and heavy-load,the research on the railway has become more and more significant.The relationship between the sleeper settlement under stable action and the ballast particle movement under the sleeper is analyzed in the proposed study.The method of coupling finite element and discrete element is utilized to study the sleeper settlement and track bed settlement.A 500 mm×230 mm×160 mm simplified sleeper cuboid model with a reduction ratio of 8∶1 is established by using finite element software,and the element nodes of the sleeper are extracted.The discrete element replacement of node coordinates is implemented through the discrete element software EDEM API to construct the sleeper discrete element model,and uses spherical particles to splice ballast particles of different shapes to complete the sleeper-track bed discrete element model.The discrete-element software is adopted to build the sleeper-track bed shrinkage model.At the same time,a test model of the same size as the sleeper model is established,and the validity and reliability of the sleeper-track bed model was determined through comparison and verification.The sleeper and track bed settlements under different excitation frequencies are analyzed,and the sleeper settlement law is obtained.It is determined that the sleeper settlement reaches the maximum when the excitation frequency reaches 36 Hz during the stabilization process.The relationship between the sleeper settlement and the stabilization operation time is obtained.As the stabilization process proceeds,the track bed settlement increases,and the settlement effect in the area directly below the sleeper is better.