Study On Dynamic Characteristics Of No.12 Speed-up Turnout

China’s existing busy trunk railway undertakes most of the transportation tasks of China’s railway,covering the main economically developed areas and key cities and regions in China,and the speed-up turnout occupies an important position in China’s trunk railway,with a large number and a wide variety.Turnout,as the core equipment of railway track,is also the weak link of track components,which has restricted the overall process of railway speed-up in China for a long time,especially the fixed frog turnout,which has a special structural form.Because of the harmful space,vehicles will cause strong impact and vibration when passing through the turnout,This kind of impact and vibration will worsen the working conditions of the turnout,resulting in a variety of turnout diseases.Secondly,the rail wear in the switch area is also the key factor affecting the working conditions of the turnout.Therefore,it is necessary to study the wheel rail interaction in turnout area and predict the rail wear law.In this paper,using um software,the models of Speed-up Passenger car,C64 freight car and three different types of No.12 speed-up turnout are established.The turnout model and vehicle model are reasonably simplified.Because the speed has a great influence on the dynamic response of the turnout area,and the heavy load has a great influence on the wear of the turnout area,this paper first simulates the dynamic response of the Speed-up Passenger car passing through three different types of No.12 speed-up turnout in reverse and straight reverse directions,and the results show that:(1)in the turnout area,the transverse effect between the wheel and rail is the most obvious,and in the frog area,the wheel rail interaction is the most obvious The vertical effect is the most obvious;compared with the high-speed turnout,the wheel rail vertical force will be greater in the frog area;compared with the side reverse,when the vehicle passes through the turnout directly and reversely,the rail vertical acceleration is larger,because the vehicle speed is higher when the vehicle passes through the turnout directly and reversely,and the wheel rail impact mainly occurs in the vertical direction.(2)Among the three different types of No.12 speed-up turnouts,the distance from each variable section position of special line 4249,tie line 004 and special line 4253 to the tip of switch rail increases from small to large,and the comparison of the maximum derailment coefficient is as follows: special line 4249 > tie line 004 > special line 4253.And the probability of derailment is higher when the vehicle passes through the switch area and frog area than other locations.(3)When the vehicle passes through the frog area of No.12speed-up turnout,the wheel load reduction rate increases to 1 instantaneously,but the exceeding time is less than the limit value of 0.035 s,so the possibility of derailment is not great.This paper studies the rail wear law in the switch area of C64 freight car when it passes through No.12 speed-up switch in reverse direction or straight reverse direction.The results show that:(1)the side wear of curved switch rail is more serious than that of straight switch rail,and the vertical wear of straight switch rail is more serious than that of curved switch rail.The side wear degree of straight stock rail is similar to that of curved stock rail,and the values are small.(2)At the stage of wheel load transition,the wear of curved switch rail is mainly distributed in the concentrated area of switch rail shoulder.After the end of wheel load transition,the curved switch rail is fully loaded and the wear distribution is expanded.(3)When the vehicle passes through three different types of No.12 speed-up turnout,the farther the switch rail variable section position is from the switch rail tip,the smaller the wear rate and the maximum wear depth of the switch rail.