Semi-analytical method to identify dynamic load in time domain

A semi-analytical method for dynamic load identification in time domain was proposed based on the approaches of modal space transformation, least square fitting and modal superposition. The problem of dynamic load identification was converted to the identification of modal coordinate functions by means of modal space transformation; using the structural characteristic parameters and dynamic responses at some given degrees of freedom as the inputs of load identification, the least square fitting was then employed to obtain the fitting functions of modal coordinates; finally, the dynamic loads in time domain were identified in the light of the principle of modal superposition and the governing equations of structural dynamics. In the identification process, acceleration responses derived from simulation and experiment were taken respectively as the inputs. The comparisons between the identified loads and the real ones show that, the method can meet the requirements of identifying the magnitudes of dynamic loads and their locations.