STRENGTH AND STABILITY OF RAILWAY TRACKS .2. DETERMINISTIC, FINITE-ELEMENT STABILITY ANALYSIS

A previous paper [F. Arbabi, A. N. Sherbourne and H. A. El-Ghazaly, Comput. Struct. 38, 681-693 (1991)] presented a simple probabilistic finite element analysis of the interaction between load and deflection in the context of the standard beam on elastic foundation model in which both the vertical load and subgrade response can be expressed statistically. In this study an analytical formulation and computer program is developed for stress and stability analysis of track under static, deterministic loads. The formulation is also based on the finite element method. A bifurcation by bulking analysis allows the determination of all instability modes, including lateral (gauge widening) and torsional buckling (rail overturning), from a zero displacement reference position. A program allows complete flexibility in terms of rail profile and unit weight, input loads involving vertical, lateral and longitudinal components and four types of foundation restraint affecting vertical and lateral displacements and rail extension and rotation. While no attempt is made to derive specific values or relationships between these components of load or foundation moduli, the analysis extends the conventional beam on elastic foundation model, which has heretofore found considerable application in track related problems.