Force Identification Based on Sensitivity in Time Domain

Abstract

A new method is proposed for identifying the time history of the input excitation using the dynamic response of the structure. The sensitivities of dynamic response with respect to the parameters of the input force are calculated in the time domain. These sensitivities are used to update the parameters of the identified force(s) iteratively in the inverse analysis. Both sinusoidal excitation and impulsive force are used in the simulation study. Three numerical examples show that the proposed method is effective and highly accurate in identifying the force(s). Both the effects of measurement noise and modeling error of the structure are found negligible on the accuracy of the identified force in the studies. The proposed method is further verified with laboratory measurements from a steel bar under sinusoidal excitation with very good results.