A novel load identification method on vibration test

A novel combined iteration method of load identification for the complex nonlinear structure is presented on the vibration test. This method realizes load identification of complex nonlinear structures by iterating the finite element method and the active control method. First, the finite element models of complex nonlinear structures are simplified to form the controlled plant. Then under the selected control law, the controller is designed to make the response power spectrum density of the measured point meet the specified spectral type, thus the input of the controller taken as the approximation of the excitation, namely the identified load, is obtained Finally, the validity of the load is checked by the response of nonlinear finite element. The excitation is determined on condition that the response power spectrum density of measured point is given. For a conical shell-belting combined structure, the numerical study of the load identification demonstrates the validity of combined iteration method, which can play a guiding role in the load identification of vibration test respecting aerospace structures, such as missile, rocket and so on, making great contribution to the development of the aerospace industry.