The method of moment for identification of distributed dynamic load on plate structure

Abstract

The identification (or reconstruction) of dynamic load is the second kind of the inverse problem in structural dynamic analysis, which is a process of reconstructing load applied to structure in case of structural dynamic model and information of structural response. When it is difficult to measure the load applied to the structure with acquisition equipment, the identification technology of dynamic load makes it possible for obtaining external load, so its researches have an important theoretical value and practical prospects. The elastic thin plate is the common load-carrying structures in engineering, and the identification of dynamic load on the plate is very meaningful. The paper presents a new method called method of moment for identification of distributed dynamic load on the plate structure. At first, the two-dimension orthogonal polynomial is constructed, which is employed as base functions for Generalization Fourier Expansion, and then the infinite dimensions function is transformed into finite dimension parameters. Secondly, the relationships are built between the finite dimension parameters and the structural response. Thirdly, the parameters can be obtained by the inverse algorithm or optimization algorithm. At last, the distributed dynamic load can be reconstructed by the finite dimension parameters. The results of computation simulations and experiment show the method is correct theoretically, effective and feasible in engineering practice.