车辆气动力展向相关性传递函数及其对桥上运动车辆响应的影响

为研究运动车辆气动力的展向相关性对桥上运动车辆响应的影响,在分析运动车辆顺风向和竖向脉动风速谱的基础上,发展出一种新型的运动车辆脉动风速相干函数形式,推导出与顺风向和竖向脉动风速对应的运动车辆气动力的展向相关性传递函数,并根据"余弦规则"得到作用在运动车辆上的抖振力谱.通过建立列车-轨道-桥梁多体系统耦合振动仿真模型,...

Transfer Function of Spanwise Correlation of Vehicle Aerodynamic Forces and Its Effects on the Responses of a Vehicle Running on a Bridge

To study the effects of the spanwise correlation of vehicle aerodynamic forces on the responses of a vehicle running on a bridge, a new form of the fluctuating wind coherence function relative to a running vehicle was developed based on its longitudinal and vertical fluctuating wind power spectra. The transfer functions of the spanwise correlation of the vehicle aerodynamic forces, corresponding to longitudinal and vertical fluctuating wind speeds, were proposed. In addition, the spectra of buffeting forces acting on the running vehicle were obtained in accordance with the cosine rule. By establishing the coupling vibration simulation model for a rail vehicle-track-bridge multibody system, a single rail car running on a typical high-speed railway bridge was considered as an example, and the effects of the above-mentioned transfer functions on the responses of a vehicle running on the bridge were investigated for different vehicle speeds, wind speeds, and terrain surface types. The results indicate that the root mean square (RMS) values of the vehicle responses decrease to different degrees when the above-mentioned transfer functions are considered, particularly for the lateral and vertical accelerations of the car body. When the vehicle speed is 40 m·s^-1, the relative errors for the RMS of the lateral and vertical accelerations of the car body in the cases with and without consideration of the transfer functions are as high as 40.6% and 36.6%, respectively. However, the relative errors for the RMS of the vehicle responses gradually decrease in value as the vehicle speed increases. As the wind speed increases, the relative errors for the RMS of the wheel load reduction rate and wheel-rail vertical force gradually increase; however, the relative errors for the vertical Sperling index and the RMS of the wheel-rail lateral force first increase and then decrease. When the terrain surface type changes from A to D, the relative errors for the RMS of the accelerations and Sperling index of the car body gradually increase; however, the relative errors for the RMS of the wheel-rail force, derailment coefficient, and reduction rate of the wheel load first increase and then decrease.