DISTRIBUTED RANDOM DYNAMIC LOAD IDENTIFICATION ON THE SURFACE OF A STRUCTURE WITH INTERVAL UNCERTAINTY

Aiming at the distributed random dynamic load identification problem on the surface of uncertain structures, a new method for identifying distributed random loads on uncertain structures is proposed where uncertain parameters are described by interval variables. The load’s power spectral density function is represented by a superposition of 2D Legendre polynomials multiplying with their corresponding coefficients in this method, then the upper and lower bounds of the 2D Legendre polynomial coefficients in the load model are further identified by the power spectral density function of the structural strain by using the interval expansion theory, and the interval boundary values of the load’s power spectral density can finally be reconstructed by the identified coefficients. The correctness of the method is verified by a numerical example on a four-sided simply-supported plate, the method is further applied on the identification of a turbulent boundary layer loading on a rudder structure. Identification results show that the interval boundary value of the identified power spectral density function can fully cover the true load value, and that the method is capable of identifying the real random fluctuating pressure load on the surface of aircraft structures, which can provide real and reliable load information for the structural design of aircraft.