高速道岔弹性铁垫板刚度劣化规律及对提速的影响

对高速道岔弹性铁垫板的伤损发展及刚度演变过程进行了跟踪试验；基于实测数据，建立了车辆-道岔耦合动力学计算模型，分析了弹性铁垫板刚度劣化对车辆-道岔动力性能的影响，研究了刚度劣化状态下高速道岔对进一步提升运营速度的适应性。研究结果表明:随着高速道岔弹性铁垫板的长期使用，出现橡胶老化、开裂、分离、脱落，铁件锈蚀等伤损；有砟、无砟道岔铁垫板动静刚度比变化均较小，但静刚度均有所增大，有砟道岔铁垫板静刚度初期即有明显变化，上道3年增幅可超60%；普通地带无砟道岔铁垫板静刚度最大可增加30%，刚度变化小于有砟道岔；高寒、多风沙地带无砟道岔铁垫板静刚度变化较快；高速道岔弹性铁垫板刚度的逐渐劣化会对动力性能产生影响；刚度劣化状态下岔区钢轨变形减小，轮轨动力冲击作用增大，安全性参数均有提高；车辆和轮对的运动轨迹基本不变，但轮对振动加剧，车体振动也有加剧的趋势；高速道岔弹性铁垫板刚度劣化状态下，运营速度的提升会导致车辆-道岔系统动力性能进一步劣化，安全和疲劳性能裕量进一步减小，刚度劣化会使高速道岔对提速的适应性下降。扩大提速范围须重点关注道岔区弹性铁垫板刚度劣化情况，对弹性铁垫板进行适当更换，确保行车安全平稳。 

Stiffness deterioration rule of elastic iron plate of high-speed turnout and its influence on speed increase

A tracking test was conducted to evaluate the damage development and stiffness evolution of the elastic iron plate of high-speed turnouts. Based on the measured data, a vehicle-turnout coupling dynamics calculation model was established, and the influence of stiffness deterioration of the elastic iron plate on the vehicle-turnout dynamic characteristics was analyzed. The adaptability of high-speed turnout to the further increase of operation speed under deteriorated stiffness was studied. Analysis results show that with the long-term use of the elastic iron plate of high-speed turnout, a series of damages appear, including rubber aging, cracking, separation, falling off, and rusting of iron components. For both the ballast and ballastless turnouts, the ratios of dynamic stiffness to static stiffness of iron plates change slightly, whereas the static stiffnesses increase. The static stiffness of the iron plate of ballast turnout shows evident changes at the initial stage, and the growing rate can exceed 60% after 3 years of service. The static stiffness of the iron plate of the ballastless turnout in the general area can increase maximum by 30%. The stiffness change is smaller than that of the ballast turnout. The static stiffness of the iron plate of the ballastless turnout changes rapidly in the cold, windy, and sandy areas. The gradual stiffness deterioration of the elastic iron plate of high-speed turnout has an effect on the dynamic performances. Under stiffness deterioration, the rail deformations in the turnout zone decrease, the wheel-rail dynamic interactions increase, and the safety parameters increase. The moving trajectories of the vehicle and wheelset are basically unchanged, but the vibration of both the wheelset and vehicle intensifies. Under stiffness deterioration of the elastic iron plate of the high-speed turnout, the increase in operation speed leads to further deterioration of the vehicle-turnout system dynamic performances, and the margins of safety and fatigue further reduce. The stiffness deterioration reduces the adaptability of the high-speed turnout to the speed increase. To expand the scope of raising speed, the stiffness deterioration of the elastic iron plate in the turnout zone should be considered. Some elastic iron plates should be replaced appropriately to ensure the running safety and stability. 2 tabs, 9 figs, 30 refs.