Hybrid modal data for dynamic response reconstruction in the premise of incomplete structural model

Dynamic response reconstruction plays an important role in structural health monitoring. Model-based response reconstruction for complex civil structures is limited by the extraction of modal data: (1) the finite element model (FEM) is difficult to precisely establish and (2) numerous DOFs lead to low computational efficiency. A response reconstruction strategy based on hybrid modal data is proposed, in which the structure is divided into a finite-element-driven component (FC) and an experiment-driven component (EC). Modal data of FC is derived from accessible FEM. EC with complex composition is replaced by an experimental representation. A part of FC is used as the transmission component (TC) to avoid additional design cost in the decoupling test. TC and FC models are processed by the Craig-Bampton approach to reduce matrix dimension and computation cost. In the full model, modal data at FC and EC is calculated by the eigen solution and transmissibility of the frequency response function. Numerical and experimental studies are conducted on a truss tower and a plate-railing assembly.