基于多尺度小波谱的桥梁结构非一致地震响应分析研究

基于小波理论揭示了大跨度桥梁在非一致地震激励下的输入输出关系。在地震输入方面,利用小波理论,将地震波模拟为非平稳随机过程,在模拟过程中不但考虑了地震波幅值及频率的非平稳特性,而且该荷载模型可以同时考虑大跨结构多点激励问题;在结构的地震动响应方面,利用小波理论及结构的输入-输出关系,得到了结构在非一致地震激励下结构响应的瞬时功率谱密度及瞬时均方值的表达形式。最后,通过一座三跨连续刚构桥的数值算例,验证了所提出方法的准确性。

Non-uniform Seismic Response of Bridge Structure Based on Multi Scale and Small Spectrum

Based on the small spectrum theory,the article opens out the import and output relationship of the long-span bridge under the non-uniform seismic excitation.In the aspect of seismic import,the small spectrum theory is used to simulate the seismic wave into the non-stationary random process.In the simulating process,it is not only to consider the non-stationary characteristic of seismic amplitude and frequency,but also to consider the multi-point excitation of long-span structure for this load model.In the aspect of seismic dynamic response of structure,the small spectrum theory and the import and output relationship of structure are used to achieve the expressing form of instantaneous power spectral density and instantaneous mean square value of the structure response under the non-uniform seismic excitation.Finally,the article validates the accuracy of the proposed method by the numerical computation of a three-span continuous rigid-frame bridge.