Using genetic optimisation to update experimental structures including damping

摘要

Most updating formulations define an objective function that can be adressed directly using an optimisation method or transposed in an equivalent linear problem using an updating method. In this paper, the classical RFM updating method is compared to a direct approach using genetic optimisation, applying them to two different experimental structures including damping. The first structure consists of a steel plate mounted on four rubber suspensions in which we try characterize the viscoelastic properties. The initial FE model is directly established (the dynamic behaviour can be modelised quite simply) and then updated by the two approaches defining four correction parameters. In both cases, the influence of the updating frequencies is studied. The second structure consists of a steel plate held in an aluminium block by two wedge-lock slides (the clamping level is defined by the torque applied on both slides) in which we try to establish and enhance a FE model that idealizes the dynamic behaviour. Ten potential corrections parameters are reduced to two parameters using a modified SVD localisation technique. The model is updated and the influence of the torque applied to the wedge-lock slides is studied.