Simultaneous identification of the load and unknown parameters of the structure based on the perturbation method

Abstract

For when a structure is both subjected to unknown loads and characterized by unknown parameters and structural parameter identification and load identification algorithms cannot be applied under these circumstances, this article proposes a new algorithm based on the perturbation method for the simultaneous identification of the load and unknown structural parameters using a few response points. The impulse response matrix is expanded with respect to the unknown parameters, and then the load term is combined with the unknown parameter perturbation term to generate the parameter–load term; finally, the load and unknown parameters can be simultaneously identified by iteration. The proposed algorithm is verified by an example of a 10-storey shear frame, and the effect of noise level, the number of response points, and the truncation ratio, which is a parameter introduced to improve the accuracy of the proposed algorithm, are studied. Moreover, the effect of the distribution of response points is discussed for another example of a simply supported beam, and the results show that when the response points are distributed over the full beam, the error is obviously smaller than when the response points are distributed over only part of the beam.