Determining the dynamic characteristics of an existing timber belfry structure and impact on FEM modelling

Abstract

The paper studies the assessment of the dynamic characteristics of an existing historic timber belfry structure using FEM modelling and dynamic identification tests performed on a structure. The analysed structure undergoes geometrically measurement, including elements inspection, and on this basis the corresponding initial FEM model was built. The initial model including actual dead loads was computed to achieve dynamical and static calculations results, including eigenmodes and modal masses. On the belfry structure, dynamic identification tests were performed using accelerometers arranged in places of expected maximum amplitudes for belfry parts. The same initial model was calibrated according to the data achieved from computing in-situ identification tests (FFT spectrum analysis) and recalculated for static and dynamic results. Computed results from the initial and calibrated models were compared, presented and discussed. Brief summary includes conclusions from analysis and contribution to researches on belfries dynamics.