基于不同轨道谱的车桥动力相互作用指标对比分析

Comparative analysis for train-bridge interaction indicators based on different track spectra

为了分析不同轨道谱对车桥动力相互作用指标的影响,以德国低干扰谱、德国高干扰谱和秦沈线轨道谱为对比对象,分析了三种轨道不平顺功率谱密度的差异,并用三角级数法获得了三种谱的时间样本。以其作为车桥系统的外加激励,计算车桥系统耦合振动响应,选用动力学指标轮重减载率、车体振动加速度、桥梁跨中动位移及桥梁跨中振动加速度进行分析,结果表明:轮重减载率大小受高低不平顺中较短波长成分的影响较明显,其规律与高低不平顺功率谱密度较短波长范围内的值相似;车体横向和竖向振动加速度则主要分别受轨道方向和高低不平顺较长波长成分影响,不平顺方向和高低功率谱之差异正好反映出了车体横向和竖向振动加速度的差异;桥梁动位移受不平顺激扰影响很小,三种轨道谱作用下的桥梁动位移非常接近;桥梁振动加速度受轨道不平顺影响较大,德国高干扰和秦沈线轨道谱明显大于德国低干扰谱作用下的桥梁振动加速度;研究结果还表明相对于桥梁竖向振动加速度,轨道不平顺对桥梁横向振动加速度的影响更显著。

In order to analyze effect of train-bridge interaction indicators based on different track spectra, taking German high speed low disturbance spectrum, German high speed high disturbance spectrum, and Qinhuangdao-Shenyang line track spectrum as comparative objects, the differences among three kinds of track irregularity power spectral density were analyzed, and the time samples of three kinds of spectra were obtained with the trigonometric series method. Numerical analysis of train-bridge coupled vibration was conducted with three kinds of track irregularities as external excitations. Wheel unloading rate, car-body vibration acceleration, mid-span dynamic displacement of bridge, and mid- span acceleration of bridge were selected as dynamic indicators for comparison. The results showed that the effect of shorter wavelength components of vertical profile irregularity on wheel unloading rate is obvious, and the law is similar to the variation of the power spectral density of vertical profile irregularity within a range of shorter wavelength ; the car-body lateral and vertical vibration acceleration are mainly affected by longer wavelength components of alignment and vertical track irregularity respectively, and the difference between alignment and vertical irregularity power spectra reflects the difference between car-body lateral and vertical vibration acceleration; the effect of irregularity excitation on dynamic displacement of bridge is very small, and the dynamic displacements of bridge are very close to under three kinds of spectrum; the impact of track irregularity on bridge vibration acceleration is bigger, and bridge vibration accelerations under German high speed high disturbance spectrum and Qin-Shen line track spectrum are significantly larger than that under German high speed low disturbance spectrum; in addition, the impact of track irregularity on bridge lateral vibration acceleration is more obvious than that on bridge vertical vibration acceleration.