轨道结构设计的计算机方法

Computer Method for Design of Railroad Tracks

详细论述了美国肯塔基（ＫＥＮＴＲＡＣＫ）轨道模型的分析方法．肯塔基模型将轨道结构处理成材料非线性的三维问题．利用单个荷载对有限根轨枕的响应及叠加原理，得到了多个荷载作用下轨道结构的挠度矩阵．ＫＥＮＴＲＡＣＫ程序系统采用了两个破坏准则作为设计依据：一是控制道床底部出现的最大拉应力或拉应变；二是控制道床最大永久沉降或最大竖向压应力．控制点的应力或应变值用作轨道损伤计算．据此，可估算轨道的设计寿命．

The analyzing method for KENTRACK railroad model is comprehensively discussed in this paper. KENTRACK model considers the railroad track as a three dimensional system with the nonlinear material properties. By using the distribution of a single wheel load over a limited number of ties and the superposition principle, the flexibility matrix for railway structure under multiple wheels loads is developed. Two failure criteria are used in KENTRACK for design purposes: one is the maximum horizontal tensile stress or strain at the bottom of ballast, and the other is the maximum vertical permanent deformation and the maximum vertical compressive stress. These stress and train are used for damage computations. Finally the design life for railroad tracks can be predicted.