【摘要】 车体设备舱底板疲劳可靠性受振动和气动载荷等多种因素的影响，致其更易于发生疲劳损伤，其疲劳可靠性是车辆安全运用中不容忽略问题。以某型动车组车体设备舱底板为研究对象，完成多节车车下设备舱底板不同位置动应力测点布置，于某客运专线进行跟踪测试。基于测试动应力数据，经数字信号处理和统计计数，得到各疲劳关键测点的应力谱。结合Miner损伤理论及母材和焊缝S-N特性，计算设备舱底板及其安装梁各测点单位里程损伤及全寿命周期下等效应力幅，分析不同运行速度、明线稳态及隧道通过等运行工况变化对于应力响应特征及疲劳损伤的影响情况，分析设备舱底板动应力的频域特征及不同频段振动能量对其疲劳伤损的贡献。结果显示，运用速度对设备舱底板疲劳损伤影响较大，由200 km/h增至300 km/h时，中部螺栓安装孔边的等效应力幅增加近30 MPa。与直线运行相比，曲线通过过程对设备舱底板螺栓安装孔的应力影响并不明显，等效应力幅增加小于3 MPa。运用中处于迎风侧的设备舱底板，其损伤要一定程度大于其处于非迎风侧的情况。设备舱底板中部疲劳伤损更多来自纵向振动，纵向和横向振动均对安装孔边位置疲劳损伤有一定贡献，且以20～40 Hz频段成分的贡献为主。运行速度提高后，设备舱底板弹性振动更易被激发。隧道通过时，对22 Hz这一主频下振动幅值有明显增加，对其他主频对应幅频特征改变很小。更多还原

【Abstract】 The fatigue strength of the vehicle equipment compartment floor is affected by vibration and aerodynamic loads and other factors, so it is more prone to fatigue damage, and its fatigue strength is a safe use of the vehicle can not be ignored. Taking a certain type of railway car body equipment compartment floor plate as the research object, we completed the dynamic stress measurement point arrangement of the equipment compartment floor plate and its mounting beams, and conducted the tracking test on a dedicated passenger line. Based on the test dynamic stress data, the stress spectrum of each fatigue key point is obtained by digital signal processing and statistical counting. Combined with Miner’s damage theory and the S-N characteristics of the base material and welds, we calculate the unit mileage damage and equivalent force amplitude of each measurement point of the equipment compartment floor and its mounting beams under the whole life cycle, analyse the effects of changes in operating conditions such as speed level, open line steady state and tunnel passage on the stress response characteristics and fatigue damage, and analyse the frequency domain characteristics of the dynamic stresses in the equipment compartment floor and the contribution of the vibration energy of the uneven frequency band to the fatigue damage of it. Contribution of vibration energy to fatigue damage.The results show that: Compared with the straight line operation, the curve through process does not have a significant effect on the stress on the bolt mounting holes of the equipment compartment floor plate, the increase of the equivalent stress amplitude is less than 3 MPa.The application of the equipment compartment floor plate in the windward side of the damage to a certain extent than in the case of the non-windward side of the equipment compartment floor plate. The fatigue damage at the centre of the equipment compartment floor plate is due more to longitudinal vibration, and both longitudinal and lateral vibration contribute to some extent to the fatigue damage at the edge of the mounting holes, with the contribution of the 20-40 Hz component being dominant. As the speed of travel increases, the elastic vibration of the equipment compartment floor plate is more likely to be stimulated. When passing through the tunnel, there is a significant increase in the vibration amplitude at the principal frequency of 22 Hz, and there is little change in the corresponding amplitude and frequency characteristics of the other principal frequencies.更多还原