OPERATIONAL MODAL ANALYSIS OF VEHICLE SYSTEM BASED ON SSI UNDER OPERATIONAL CONDITIONS

The modal parameters of linear vehicle system are analyzed by the theoretical modal parameter analysis method first, and then SSI based on operational conditions is presented to form the estimation formula of modal parameters of linear vehicle system. At last, the modal parameters of linear vehicle system are identified by SSI after its vibration test under operational conditions, and are simultaneously compared to the results obtained by the theoretical modal parameter analysis method. Comparison results show discrepancies of 0.61 similar to 8.32 percent on modal frequencies and 3.86 similar to 11.61 percent on modal damping ratios, which implies that SSI based on the operational condition is feasible and effective, and has comparatively higher precision to meet the needs of engineering.