Load-deflection model for T-section rail press straightening process under lateral loads

Straightening is an important process in the production route of a T-section rail. The three point reverse bending method has been utilized extensively for rail straightening process due to its apparent simplicity and good flexibility. Therefore, this paper studies the load-deflection model in the three point bending and its application for T-section rail press straightening process under lateral loads, considering the work-hardening materials. An elastic-plastic power-law hardening model of the material is adopted. The analytical formulas of the relationship between the loading force and the bending deflection is given in the elastic deformation stage and the elastic-plastic deformation stage during the bending process. The corresponding loading deflections for straightening certain initial deflections of a rail are also calculated according to the simple unloading law. The theoretical results are then compared with the experimental data of rails with different initial bending deflections. It is found that the load-deflection model and straightening model established in this study could achieve an allowable straightness error. The results of this subject can be provided as an analysis reference for the automatic control strategy of a rail straightening process.