Two-dimensional full-field displacement reconstruction of lattice towers using data fusion method: Theoretical study and experimental validation

Full-field displacement measurement of lattice tower is very important for assessing its service conditions. However, most of the existing measurement techniques or reconstruction methods only can obtain the point-type displacement or not suitable for lattice tower. To fill this gap, this paper proposes a data fusion method to reconstruct two-dimensional full-field displacement of lattice tower via strain and acceleration. First, lattice tower was simplified to thin-walled variable-section cantilever beam, then full-field displacement is calculated from the strain based on strain decomposition and modal conversion principles, and a novel data fusion algorithm is developed to fuse the strain-derived displacement and acceleration to acquire more accurate results. The effectiveness of the proposed method is verified by the numerical simulation of the transmission tower structure under wind loads, the results show that the full-field displacement can be calculated, and the reconstructed error of the highest point is only 1%. Then the parametric analysis illustrates that the proposed method has excellent performance under the influence of high sampling ratio or strong noise. The field measurements of the full-scale lattice tower are conducted to further verify the feasibility, and the results show that the reconstructed displacement value of the highest point differs from the observation value of the total station by a maximum of 5.4 mm, accounting for only 6% of the measured value.