冰块冲击作用下CRTS Ⅲ型无砟轨道板损伤及变形数值模拟分析OA北大核心CSTPCD

To investigate the impact damage of track slabs caused by detached ice blocks adhering to the underbody of high-speed trains,a dynamic finite element analysis model for the ice impact on CRTS Ⅲballastless track slab was established coupled with smoothed particle hydrodynamics(SPH)and finite element method(FEM)by utilizing the LS-DYNA software.The characteristics of the slabs deformation and damages imparted by ice blocks were analyzed and the influence of ice block radius,impact velocity,and impact angle on the patterns was also investigated.The numerical results reveal that when a cylindrical ice block impacts the track slab vertically,a bowl-shaped depression is formed on its surface,with the maximum depression depth located near the center of the impact.The diameter of the depression is similar to that of the ice block,and annular cracks are distributed around the edge of the depression.The maximum depression depth and the number of failed elements increase with the rise of the ice block radius and impact velocity,while decreasing with the increase of the impact angle.The impact angle from 0° to 15° has the most significant reduction,with a maximum depression depth and failed element number decreasing by 89％and 80％,respectively.When the ice block radius extend from 30 mm to 60 mm,the maximum depression deepens from 0.079 mm to 0.139 mm,and the number of failed elements increases from 36 to 973.Moreover,with the increase of the impact velocity from 40 m·s-1 to 100 m·s-1,the maximum depression depth and the number of failed elements increase from 0.014 mm and 0 to 0.079 mm and 36,respectively.The results can provide references for the service life assessment of track slab and speed limit of high-speed trains in ice and snow weather.