The current study investigates how to identify the structural modal for under-sampled structures.First,a resampling strategy is introduced based on the frequency domain decomposition method to identify struc-tural modal parameters at different sampling frequencies that may suffer from aliasing.Second,a modal assur-ance criterion is employed for modal matching,combined with the fan-folded model,to restore the modal param-eters that suffer from aliasing due to under-sampling,thereby recovering the true frequencies and damping ratios of the structure.Finally,through an 8-degree-of-freedom simulation model and an experimental case with a 4-level framework,it is demonstrated that the proposed method accurately identifies the frequencies,damping ra-tios,and mode shapes of under-sampled structures.Obtained results validate the correctness and feasibility of the resampling strategy,confirming that this approach effectively addresses the issue of modal identification for under-sampled structures.
维普
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