ON THE TREATMENT OF DISCRETIZATION ERRORS IN FINITE-ELEMENT MODEL UPDATING

It is well known that the eigenvalues of finite element models are inf luenced considerably by mesh refinement. Eigenvalue errors, due to sha pe function discretisation, persist in the frequency range of interest until the model is fully converged, and generally have a serious affe ct upon updated parameters. The requirement of a converged model for u pdating generally conflicts with design requirements which may be sati sfied by a Coarser mesh. A two-level Gauss-Newton approach is proposed which allows the simultaneous and efficient correction of design and updating models. The method may be applied to; modal or FRF test data. Simulated and experimental tests are conducted to illustrate the effe ctiveness of the technique.