Finite element model updating of jointed structure based on modal and strain frequency response function

Abstract

To acquire a reasonable model for structural dynamic strength analysis, a bottom-up finite element modeling and updating methodology based on multi responses is proposed. The fundamental principles of structural dynamics analysis and model updating were introduced, and the proposed strategy was applied to the case study of an L-shaped jointed structure. Components of the jointed structure were modeled sequentially, and inaccurate model parameters were updated based on the corresponding experimental modal results in the first stage. In the second stage, components were connected together by bolts. The joint interfaces were represented by thin-layer elements, and local joint parameters were updated based on strain frequency response function (FRF). Finally, the precision of finite element model (FEM) was validated by acceleration frequency response function. The results indicated that the proposed methodology is able to reduce model simulation errors in both components and the overall jointed structure. Not only can the updated model of a jointed structure reproduce the experimental results used in updating, but also predict responses that are not used in the process of model updating.