钢弹簧损伤对地铁列车-浮置板轨道振动性能的影响

Effects of steel spring damage on vibration performance of metro train-floating slab track system

为研究钢弹簧损伤对地铁浮置板轨道及列车振动的影响,基于结构动力学理论建立了钢弹簧损伤情况下地铁列车-浮置板轨道-衬砌-地基的二维整体分析模型。采用模态分析法和Newmark-β法求解车轨系统的动力响应,研究钢弹簧损伤数量、损伤程度、损伤位置及列车速度对车轨振动性能的影响。研究结果表明:钢弹簧损伤会加剧车轨系统的振动响应,且振动幅值随着钢弹簧损伤数量和损伤程度的增加而显著增大;钢弹簧损伤的分布位置对车轨振动影响显著,在相同钢弹簧损伤数量下,损伤位于同一块浮置板板端对车轨振动幅值的影响最大;在钢弹簧损伤情况下,车轨系统的各项竖向加速度随列车速度的增加而显著增大,竖向轮轨接触力及轨道竖向位移幅值则基本不受影响。钢弹簧损伤对乘客舒适度、钢轨使用寿命、周边环境振动都有不利影响,可利用车体竖向加速度、衬砌竖向加速度等敏感指标进行排查和更换,以免造成更严重的后果。

In order to study influences of steel spring damage on vibration of floating slab track and metro train, a 2-D metro train-floating slab track-lining-foundation coupled system model based on the structural dynamics theory was established considering steel spring damage. The dynamic responses of the train-track system were solved using the modal analysis method and Newmark-β method to study the effects of damaged steel spring number, damage level, damage location and train speed on the vibration performance of the train-track system. The results showed that steel spring damage can aggravate vibration responses of the train-track system, and vibration amplitudes increase significantly with increase in damaged steel spring number and damage level;distribution location of damaged steel springs significantly affects vibration performance of the train-track system, and if damaged steel spring number keeps the same, influence of all damaged steel springs being located at ends of one floating slab on vibration amplitudes of the train-track system is the maximum;if floating slabs have damaged steel springs, amplitudes of vertical accelerations of the train-track system increase obviously with increase in train speed, but vertical wheel-track contact force and track vertical displacement amplitudes basically are not affected;steel spring damage has adverse effects on passenger comfort, track service life, and surrounding environment vibration;vertical accelerations of train body and lining can be taken as sensitive indexes to detect and replace damaged steel springs, and avoid causing more serious consequences.