Modal Parameter Extraction of a Vibrating Screen Based on Poly-reference LSCE Method

摘要

In this paper a kind of modal parameter extraction scheme called poly-reference LSCE method from output only data is presented. It is based on the theory of auto- and cross-correlation functions by treating the auto- and cross-correlation functions between outputs instead of impulse response function in the traditional complex exponential method. A vibration testing experiment on a Vibrating Screen model is performed with white noise stochastic excitation. The testing data were analyzed with both the Poly-reference LSCE method and traditional LSCE to verify the proposed technique by comparison of the results. Nine modes below 78 Hz were found to be clearly stabilized. The results from two methods give an excellent agreement. It approves that the proposed method can be used to extract modal parameters for large mechanical structures in operating condition from response ―only data.