Finite element model updating using vibration test data under base excitation

Most model updating methods use measured frequency response function (FRF) data to update analytical models whereas only response functions under base excitation can be obtained in practical vibration test due to difficulties and constraints which prevent conventional FRFs from being measured accurately. This paper presents a new model updating method, which can employ measured response function data under base excitation directly for updating. Mathematical formulations using measured response function data under base excitation to identify mass and stiffness modeling errors, have been established. Through simulated numerical case studies based on a cantilever beam as well as a practical GARTEUR structure, it has been proved that the proposed method is feasible and effective when applied to the identification of mass and stiffness modeling errors. It is also shown that this method has considerable noise-resisting ability in the case where the measured response function data are contaminated by certain level measurement noise.