无砟轨道层间裂纹内动水压力特性分析

在雨水丰富和排水不畅的地区,水对无砟轨道层间裂纹扩展的影响比较突出.为研究高速列车作用下无砟轨道裂纹内水压力的分布规律及压力大小的影响因素,基于质量守恒和动量定理,采用控制体积法,导出了裂纹内动水压力分布解析式.应用有限元分析软件ANSYS和CFX,分析了荷载频率、荷载幅值、裂纹深度、裂纹开口量等对动水压力的影响.分析结果表明:沿着裂纹出口的方向,水压力呈减小趋势,其最大值发生在裂纹尖端处;动水压力与荷载频率近似呈二次方关系,与荷载幅值呈线性关系,与裂纹开口量呈一次反比关系.在幅值为10 kN、频率为5 Hz荷载作用下,水压力分布的试验测试结果与理论分析基本一致,两种方法获得的水压力峰值分别为0.177、0.161 kPa. 

Analysis of Water Pressure in Ballastless Track Crack

In the areas with sufficient rainfall and poor drainage, water in ballastless track has significant effect on the crack propagation. To analyze the distribution of water pressure and influential factors on water pressure in the ballastless track under high-frequency train load, based on the law of mass conservation and momentum theorem, the analytical expression of water pressure was deduced by using the control volume method. The finite element software ANSYS and CFX were used to analyze the influence of loading frequency, load amplitude, crack length and crack opening on water pressure. The theoretical results show that the maximum water pressure appears at the crack tip under loading, and decreases along the crack. The value of water pressure is proportional to load amplitude, square of loading frequency and inversely proportional to crack opening. At the frequency of 5 Hz and loading amplitude of 10 kN, the hydrodynamic pressure distributions resulted from experiment and theoretical computation are nearly identical, and the corresponding hydrodynamic pressure peaks are 0.177 and 0.161 kPa, respectively.