Longitudinal Force And Deformation Analysis Of Large-Sized Welded Turnout By Finite Element Program

Continuous welded turnouts are important for CWR track through the railway station. When turnouts at stations are welded with rails, before and after the turnout, an unbalanced rail longitudinal force is generated, which bring changes to the load and deformation of the turnouts, and further bring much more difficulties for the designing and maintaining of CWR track. The main purpose of the designing theory of welded turnouts is to calculate the expanding and the contracting displacements of the inner rails, the additional temperature forces of the stock rails, and to guarantee these values are within the allowable limit. Therefore, the analysis of rail longitudinal force and displacement become one of the important issues in the railway track field.Based on the finite element principle and studying on the temperature forces passing principles of continuous welded turnouts with movable point frog, the article propose a new calculating theory for continuous welded turnouts and makes a finite element model by using ANSYS to analyze the forces and deformation .The model has been applied to the theoretical calculation on two kinds of welded turnouts—No.18 turnout and No.38 turnout on the Qinhuangdao—Shenyang dedicated passenger line. From that calculation result some new important conclusions have been drawn. In addition, the data collected on site is basically consistent with that of the theoretical calculation. It is proved that the calculation theory is correct.Some influences on the temperature forces and displacements of different resistances of the welded turnouts are invested .The additional temperature forces of the stock rails and the inner rail displacements will increase with the decrease of ballast resistance. The inner rail displacements and the shear forces acted on the bolts of spacer at heel will increase with decrease of fastening resistance. Thus in the designing and maintenance of continuous welded turnout, special attention should be paid to good quality of tamping of blast, the tightness of fastening. The inner rail displacement will increase with the increase of gap limit of spacer pieces at heel, and shear force increase with the decrease of that. Therefore, the gap limit of spacer pieces at heel should beappropriate. All the results can be used to guide the structure design and the maintenanceof continuous welded turnout.