Parameter estimation of orthotropic plates by Bayesian sensitivity analysis

A method is developed to revise the elastic properties of a thin composite plate vibration model in an iterative manner such that its modified analytical responses eventually match those obtained experimentally. Once the revision process is completed, the resulting properties are considered the true properties of the plate and a non-destructive method for parameters evaluation is thus established. Formulation of a Rayleigh-Ritz model enables the calculation of the natural modes of vibration and an accurate finite element model is used to assess the confidence of these modes. Experimental modes as target responses are extracted by modal testing. Statistical Bayesian estimation is then applied to direct the adjustments of the parameters based on the discrepancies between the analytical and experimental responses. This method takes into account both the confidence associated with mathematical modelling and parameter estimates. Satisfactory convergence of the iteration scheme has been observed for several generally orthotropic glass/epoxy plates. Of all the constants determined using this approach, the elastic moduli are most accurate.