桥梁应变与挠度动力放大系数的大小关系研究

比较了简支梁桥和连续梁桥的应变和挠度动力放大系数的大小关系。首先对作用有移动常量力的简支梁和连续梁进行理论推导，分别得到了应变和挠度动力放大系数并进行了比较。为考虑动力车辆荷载影响，采用移动弹簧质量作为车辆模型建立了车桥耦合振动模型进行数值模拟。理论推导和数值模拟的结果均表明:应变动力放大系数基本小于挠度动力放大系数；两者比值受很多因素影响，其中计算桥梁响应所用的桥梁模态阶数对比值的影响较大。

COMPARISON OF DYNAMIC AMPLIFICATION FACTORS CALCULATED FROM BRIDGE STRAIN AND DEFLECTION

A comparison of dynamic amplification factors calculated from bridge strain and deflection of a simply-supported beam and a continuous beam is conducted. Firstly, the strain and deflection dynamic amplification factors are theoretically derived and compared based on a simply-supported beam and a continuous beam under the action of a constant moving force. To consider the effect of dynamic vehicle loading, numerical simulations are performed using a developed vehicle-bridge coupled model while adopting a moving spring mass vehicle model. The results from both the theoretical analysis and numerical simulation show that the strain dynamic amplification factor is less than the deflection dynamic amplification factor and that their ratio is influenced by a number of factors, among which the number of vibration modes used in calculating the bridge responses has a significant influence.