磁浮钢箱梁日照作用对车桥耦合振动的影响

Thermal Effect for Steel Box Maglev Guideway on Vehicle-Bridge Coupled Vibration Response

磁浮轨道梁日照作用下的温度变形是轨道梁静力与动力设计需考虑的重要因素,笔者根据传热学与有限元理论,结合夏季气象参数与日照辐射半经验公式,利用ANSYS建立磁浮线轨道钢箱梁日照温度场三维瞬态模型。首先,分析磁浮轨道梁的最大竖向与横向温差发生时刻的温度梯度分布,基于日照温度场分析结果,计算不同支承形式钢轨道梁的温度变形;然后,将单跨简支、双跨连续形式轨道梁的温度变形作为初始不平顺组成部分,进行车桥耦合动力响应分析。结果显示:温度效应使车体加速度、悬浮气隙幅值增幅较大,对电磁力有所增大,对轨道梁加速度及位移的放大作用则不明显,各动力响应值仍处于规范规定的安全范围内,但安全度有所降低。

The temperature deformation caused by solar radiation of the maglev track beam is an important factor to be considered in the static and dynamic design. Based on meteorological data and solar radiation semi-empirical formulas of Shanghai in summer,a three-dimensional model for a section of maglev line steel box girder with transient state analysis method has been established using ANSYS software. The temperature field is calculated according to the principle of heat conduction and finite element method. The temperature gradient distribution of the maximum vertical and lateral temperature difference of the maglev track beam is analyzed. Based on the analysis results of the sunshine temperature field,the temperature deformation of the steel track beam with different support forms is calculated. The temperature deformation of the single-span simply supported and double-span continuous form maglev track beam are taken as the initial irregularity components. Vehicle-bridge coupled dynamic analysis of the vehicle is carried out and the dynamic response is taken for analysis. Results show that the temperature effect obviously increases the acceleration of the vehicle body and the amplitude of the suspended air gap. The electromagnetic force is increased by thermal effect to a limited extent. The influence of thermal effect on acceleration and displacement for the track beam is not obvious. The dynamic response values are still within the safe range of the standard regulations,but the safety status is worse.