一种基于低通滤波的公路简支梁桥实测冲击系数计算方法

A method for calculation of tested impact factor of a simply supported girder bridge based on low-pass filtering

分析现行公路桥梁评定规范中实测冲击系数计算中存在的问题;基于动力学理论推导移动力作用下简支梁的动力响应,分析其中的振动频率成分,得到对应静态分量的频段;提出通过频域低通滤波从简支桥梁的动力响应中提取相应的静力成分的方法;通过仿真分析介绍了动挠度响应提取静力成分进而计算冲击系数的具体过程;并将该方法应用于某简支梁桥跑车试验的冲击系数计算。结果表明:该方法方便、可靠,可为桥梁评定提供参考。

Some problems existing in tested impact factor calculation of current bridge assessment specification were analyzed.The frequency components in dynamic response of a simply supported girder beam subjected to a moving force were investigated theoretically.A method using low-pass filtering in frequency domain to extract the static component from the dynamic response was proposed.Through simulation analysis,the process of extracting the static component was introduced.This method was applied to a real bridge for its static displacement extraction and impact factor calculation.The results showed that the method is convenient and reliable,it provides a reference for calculation of tested impact factor of a bridge.