未知地震激励下结构模态的识别

Model Identification of Structures Subjected to Unmeasured Seismic Excitations

利用理论分析和数值模拟相结合的方法,解决在地震激励未知的情况下框架结构模态识别的问题。首先在频域内以时程反应傅立叶变换作为输入值,然后通过比较不同点的输入值确定结构的模态,从而诊断出结构的损伤。最后对二维和三维框架结构进行数值模拟分析。结果表明,本方法在地震力未知时识别框架结构损伤具有可行性和有效性。

Based on numerical technology and analysis ,a technique is described suitable for i‐dentifying the modal model of a spatial frame in the frequency domain w hen the seismic input is unknow n both in time contents and direction .T he basic idea is that the ratio of the Fourier trans‐forms of the time‐history responses at different points of a structure is input‐independent and so it can be an experimental source for modal model identifications .Numerical applications are carried out on plane and spatial framed structures ,in most cases the results are satisfactory .