Fault identification for spring of large vibrating screen using free response

In consideration of the less-studying of fault diagnosis for damping springs of large vibrating screen(LVS),a diagnostic methodology based on free response was proposed.After analyzing the incapability of describing the whole fault properties of a vibrating screen within traditional models,a coupled dynamic model with damping and free vibration was established,followed by the downward compatibility discussion with the traditional models.Then,the analytic expression of the free vibration response was derived by the mode superposition method,based on which,peculiarities of the dynamic catastrophe as well as the vibration-strengthening were summarized.After that,the associated 3Dbar chart in time domain and waterfall spectrum in frequency domain of each clamping plate was adopted to identify locations of a single fault and an error-free spring in an experiment for 14different type of spring faults.Results finally verified capability of the proposed method for diagnosing the spring fault in a LVS.