# Concept of Thermal Shrinkage-Resistant Railroad Rail for Use in Continuous Welded Rail Track
## 2 Literature Review  
The causal sequence of rail stressing-buckled rail-track buckling has been described and formalized in the form of a mathematical model in a fundamental way, for example, in [1,7,8]. Laboratory studies of the rail-sleeper system in terms of the rail stressing phenomenon are presented, for example, in [9,10]. When it comes to rail stressing, no publications have been found proposing an analytically supported approach to reducing this phenomenon by changing the shape of the rail during production. One exception to this is patent [11], which proposes a rail that has horizontal cutouts in the shape of holes made to reduce the weight of the rail. This solution is characterized by the presence of horizontal cutouts that interfere with the structure of the rail to a significant degree, which can lead to the formation of the notch phenomenon, significantly reducing the strength of rails made according to this description. Moreover, this solution does not take into account the dimensions of railroad sleepers in the placement of horizontal cutouts in the rail. In [12], an improvement of the rail manufacturing process resulting in a reduction in the inherent stresses in the rail was proposed. One of the trends in countering track buckling found in the literature is the development of methods and tools for the early detection of stresses in the rails, enabling action to be taken to pre-empt track buckling. This approach is presented in scientific and research papers [13; 14] and patents [15; 16; 17; 18; 19; 20; 21]. An interesting idea is to counteract the buckling of the track by modifying the \"sleeper-ballast\" system. Publication [22] proposes the use of newly shaped railroad sleepers and an upgraded railroad ballast to reduce track buckling. A special case of a track buckling study, in which wooden and reinforced concrete sleepers are used alternately, was considered in [4], where the beneficial effect of alternating the use of different types of sleepers on track buckling was found on the basis of a 3D finite element analysis of models. In [23], an evaluation of the effect of the shape of the railroad sleeper on ballasted track resistance is presented using discrete element modeling (DEM). In [24], improved sleeper resistance was demonstrated in the ballast when using sleepers fitted with additional anchors versus conventional sleepers. Studies to determine the preferred temperature for rail installation in CWR track are presented in [25; 26]. Patent [27] presents an active way to counteract track buckling by reheating or cooling the rails, depending on their current temperature. There are also numerous coatings used to envelop the rail that are aimed at lowering its temperature when exposed to sunlight. According to [28], \"Some coatings are able to reduce the temperature of the rail by up to 10 degrees\". A major problem is controlling track buckling on railroad track curves. In [29], a FEM-based model of the behavior of continuous welded rail (CWR) on a small radius curve (250 m) is presented. Patent [30] presents a solution to the problem of track buckling on a curve by specifically reinforcing the subgrade. Patents [31; 32] propose to counteract track buckling using a special attachment of the rail to the sleeper to allow for the controlled lateral movement of the rail with respect to the track axis. The track buckling phenomenon is particularly dangerous in the area of bridges. The track structure used on bridges is less resistant to lateral loads and more prone to buckling. There are publications [33; 34] describing methods to reduce the buckling of railroad track on bridges, including ones involving different rail profiles [35]. Patent [36] presents a device for reducing future track buckling while the track is still under construction. Publications [37; 38] present analytical methods for determining the buckling of structures in objects with a specific shape and specific surroundings.