基于反力替代的弹性支撑连续梁桥自由振动

将连续梁桥简化为中间弹性支撑的多跨连续Bernoulli—Euler梁模型，以支座反力替代弹性支撑的连续梁相当系统，采用Laplace正反变换，根据连续梁的边界条件及弹性支撑处的变形相容条件，得出频率特征方程、自振频率及相应模态．结合数值算例，将文章理论推导方法所得结果与有限元法所得结果对比，验证了理论推导与计算程序的正确性；分析了在不同边界下，中间弹性支撑刚度变化时，连续梁各阶频率的变化规律．

Free vibration analysis of continued beams with intermediate elastic bearing based on reaction force alternative

The model analysis of continuous uniform Bernoulli-Euler beams with intermediate elastic bearing is studied. For the equivalent system of continued beams which support reaction force substituted for elastic bear- ing, using Laplace transformation to obtain the frequency characteristic equations under the boundary conditions of continued beams and the deformation compatibility conditions at the elastic bearing. It is obtained frequency from the frequency characteristic equations, and corresponding mode of continued beams. According to numeri- cal example, the comparison between the result from this paper and the result from FEM is conducted for the va- lidity. The effects of elastic bearing on frequency of continued beams under different boundary conditions are discussed.