汽车荷载作用下曲线简支梁桥的动力响应

Dynamic response of simply-supported curved girder bridges under vehicular loads

在建立6参数1/4汽车模型和每节点7个自由度的桥梁有限元模型的基础上,研究了汽车荷载作用下曲线简支梁桥的动力响应.通过数值模拟,分析了简支弯箱梁桥的动力特性,同时研究了不同的曲率半径、偏心距、弯扭刚度比、行驶速度等因素对动力放大系数的影响.结果表明:并非所有的前5阶桥梁自振频率随曲率半径的增加而增加;当参数改变时挠度和扭转角的动力放大系数的变化规律并不相同,相同条件下扭转角动力放大系数的变化较挠度动力放大系数的变化明显.

This paper,for which a finite element bridge model with 7 degrees of freedom per node and the 1/4 vehicle model with six parameters was established,aims at analysis of the dynamic response of curved girder bridges under vehicular loads.In the numerical simulation,the vibration characteristics of simply-supported curved girder bridge are analyzed,and the effect to the impact factors is also studied for different radiuses of curvature,eccentricities,ratios between bending and torsion stiffness,and vehicle speeds.The simulated results show that not all the first 5 natural frequencies increase with the variation of radius of curvature.The impact factor variations of vertical deflection and torsion angle are not uniform when parameters change,and the impact factor of torsion angle will be much larger than that of vertical deflection under the same conditions.