"Finite element model updating and probabilistic analysis of timber-concrete composite beams"

Timber-concrete composite beams are an increasingly common design solution for medium to long span floors in new buildings. Thus, there is a significant need for accurate models and analysis tools to predict the response and performance of timber-concrete composite beams. In this paper, a nonlinear finite element (FE) frame model with deformable shear connection is adopted to estimate the short-term structural response of timber-concrete composite beams for which experimental results are available. The FE model is used in conjunction with a probabilistic analysis methodology that explicitly accounts for the uncertainties in the parameters describing the constitutive models for timber, concrete, and shear connectors. The objectives of this study are: (1) the evaluation of the variability of global and local structural response quantities due to the uncertainties in the constitutive parameters of timber, concrete, and shear connectors; and (2) the analysis of the correlation between experimental measurements and numerical results based on FE models in which the values of the constitutive parameters are set equal (i) to their experimentally identified mean values, and (ii) to optimized values obtained through FE model updating, respectively. The results presented in this study show that uncertainties in the constitutive parameters of timber, concrete, and shear connectors have a significant influence on the correlation between experimental and numerical results. In addition, the optimal values of material parameters obtained using the FE model updating procedure might show substantial variations with respect to the parameters’ mean values as identified in experimental testing. Prospective developments directed toward design applications and based on the obtained results are also discussed.