Stability of continuous welded rails: A state-of-the-art review of structural modeling and nondestructive evaluation

Continuous welded rails (CWR) are track segments welded together to form a continuous miles-long track. With respect to mechanically-jointed rails, CWR are stronger, smoother, require less maintenance, and can be traveled at higher speeds. Despite these advantages, CWR are prone to fracture during cold seasons and to instability during warm seasons when the increase in the steel temperature induces extreme compression. To better understand buckling mechanism, engineers studied the structural behavior of rails under static and dynamic loads. Some of these models represent the basis of noninvasive methods to measure longitudinal stress. Both structural analyses and nondestructive evaluation methods are tools to predict the temperatures and the field conditions at which rails experience extreme tensile or compressive stress. This article reviews the last three decades of research and development on the structural analysis and nondestructive evaluation of CWR. The scope of this document is to provide a holistic view of the developments in rail engineering and nondestructive evaluation relevant to the problem of thermal buckling. Advantages and limitations of the analyses and of the nondestructive methods are discussed based upon the information available in the scientific literature. Additionally, any knowledge gap to be addressed by the scientific community in the years to come is identified and discussed.