A Comparative Study On The Mechanical Properties Of Rail Fastenings In High Speed Railway

As the main part of railway track structure,high-speed railway fastener system is an important part of connecting rail and supporting rail.It can alleviate the vibration and impact of train through elastic deformation.With the in-depth development of high-speed,heavy load and speed-up transportation,the dynamic interaction between wheel and rail becomes more and more serious.Limited by large-scale construction work,changeable lower foundation and other factors,the rail fastener system is increasingly damaged under the high-frequency impact load of the train.As the main type of fastener in our country,spring bar clip has more damage and failure in use.However,according to the current research of the damage and failure of spring strip clip,it is difficult to solve the problem of damage and failure of spring strip clip fundamentally.Therefore,it is necessary to try to change the clip from spring strip to spring shell,so as to solve the problem of elastic strip damage from the root In this paper,the finite element models of WJ-7 fastener system and Japan straight knot8 fastener system are established to study the deformation and stress characteristics of X2 Spring strip clip and C spring shell clip under the standard and non-standard installation conditions.At the same time,the influence of rail vertical displacement and rail head lateral displacement on the mechanical properties of the two types of fasteners is studied;the elastic range,stiffness,stress level and evaluation index of the two spring clips under the same buckle pressure are compared;the increase of the buckle force,the change range of stress and the strength surplus under the vertical and lateral displacement of rail are compared.The results show that the weak point of the X2 spring strip clip lies on the upper surface of the arc behind the Spring strip clip;The biggest disadvantage of X2 spring strip clip is that its safety reserve is insufficient due to the stress concentration.The advantage of X2 spring strip is that it has strong holding capacity of buckle pressure and good elasticity.The stress weak point of C spring shell clip is located at the upper part of the circular arc at the bottom of the C spring shell clip and near the bolt hole;Its biggest disadvantage is that the buckle pressure loss is serious under the action of vertical displacement of the rail.Its advantages are sufficient strength surplus,strong ability to resist rail tipping,and its fatigue life is higher than that of X2 spring strip clip except that the rail floats excessively.In general,when the vertical displacement of the rail caused by the train is small,the comprehensive performance of the C spring shell clip is better than that of the X2 spring strip clip.Compared with the X2 spring strip clip,the C spring shell clip is more suitable for the CWR on the bridge to reduce the interaction between the beam and rail.This thesis provides some guidance for the selection,follow-up research and optimization of rail fastenings in China’s high-speed rail fastening system.