Distributed Dynamic Load Identification on Irregular Planar Structures Using Subregion Interpolation
Yi Zheng, Shaoqing Wu, Qingguo Fei
Abstract
Spatially distributed load on aircraft structures is difficult to obtain due to the limitation of measurement technology, the complexity of load and the external environment of the aircraft during flight, etc. A load identification method based on a subregion interpolation technique is proposed to indirectly estimate the distributed dynamic load from measured strain data on planar structures. The load distribution area is discretized into several subregions and the load distribution function in each subregion is represented by a set of local interpolation functions multiplied by their corresponding coefficients. A modified Green’s function matrix is formulated to establish the relationship between the local distributed dynamic load in the domain composed of the subregions sharing the same node and the structural response data. Hence, both the load’s distribution and time histories can be identified from structural response by solving the new formulated inverse problem. Numerical simulations on a flat cantilever plate and a planar structure with irregular geometry are conducted to show the effectiveness of the proposed method. Results show that the proposed method has better adaptability on the types of load distribution and structural configurations than the existing methods.