W1型弹条扣压力与疲劳性能的试验研究

W1型扣件弹条是高速铁路无砟轨道常用的弹条之一,高速铁路弹条在实际工作时受到反复多变的荷载作用,其强度会逐渐变化并发生疲劳破坏.以W1型弹条为列,首先,将W1型弹条的原材料60Si2 MnA弹簧钢加工成试验所需试件进行静力拉伸试验;其次,对W1型弹条进行应变电测试验测出弹条各部位的应力变化;最后,通过MTS810伺服液压试验机对W1型弹条施加三种不同的循环荷载工况,研究弹条在循环荷载作用下其扣压力和中端圆弧位移的变化规律.通过试验数据拟合出弹条中端圆弧位移和扣压力的函数方程式.结果 表明:弹簧钢的屈服强度为1600 MPa,抗拉强度为1900 MPa.弹条内侧圆弧应力值最大也是最易断裂的位置和25 kN是弹条的最佳安装预压力,随着疲劳荷载的循环次数增加,弹条扣压力与中端圆弧位移呈反相关系,弹条在5、7.5、10 kN循环荷载作用下的疲劳寿命分别为82万、19万、7万次.

Experimental Research on Buckle Pressure and Fatigue Performance of W1 Type Spring Bar

W1 type fastener spring bars are one of the commonly used spring bars in ballastless tracks of high-speed railways. High-speed railway spring bars are subjected to repeated and variable loads during actual work, and the strength of the spring bars will gradually change and fatigue failure will occur. This article takes W1 spring bar as a column. First, the raw material 60Si2MnA spring steel of W1 spring bar is processed into test specimens for static tensile test, and the yield strength of spring steel is 1600MPa and the tensile strength is 1900MPa; Then, the W1 elastic bar is subjected to a strain electrical test to measure the stress changes of each part of the elastic bar, and the position where the stress value of the inner arc of the elastic bar is the largest and the most easily broken is obtained, and 25KN is the best installation preload of the elastic bar; Three different cyclic loading conditions are applied to the W1 spring bar by the MTS810 servo hydraulic testing machine, and the change law of the spring bar"s buckle pressure and the arc displacement of the middle ring under the cyclic load is studied. The test shows that the change with the fatigue load The number of cycles increases. The spring bar buckle pressure and the arc displacement of the center circle are in antiphase relationship. The fatigue life of the spring bar under 5KN, 7.5KN, and 10KN cyclic loads are 820,000 times, 190,000 times, and 70,000 times respectively. The relationship between the arc displacement of the middle circle of the spring bar and the buckle force is fitted by the test data.