A global optimization approach applied to structural dynamic updating

In this paper, the application of stochastic global optimization tech- niques, in particular the GlobalSearch and MultiStart solvers from MatLab®, to improve the updating of a structural dynamic model, are presented. For com- parative purposes, the efficiency of these global methods relatively to the local search method previously used in a Finite Element Model Updating program is evaluated. The obtained solutions showed that the GlobalSearch and MultiStart solvers are able to achieve a better solution than the local solver previously used, in the updating of a structural dynamic model. The results show also that the GlobalSearch solver is more efficient than the MultiStart, since requires less computational effort to obtain the global solution.Fundação para a Ciência e a Tecnologia (FCT

Analytical prediction of the flexural response of external rc joints with smooth rebars

An analytical model in a closed form able to reproduce the monotonic flexural response of external R.C. beam-column joints with smooth rebars is presented. The column is subjected to a constant vertical load and the beam to a monotonically increasing lateral force applied at the tip. The model is based on the flexural behavior of the beam and the column determined adopting a concentrated plasticity hinge model including slippage of the main bars of the beam. A simplified bilinear moment-axial force domain is assumed to derive the ultimate moment associated with the design axial force. For the joint a simple continuum model is adopted to predict shear strength and panel distortion. Experimental data given in the literature are utilized to validate the model. Finally, the proposed model can be considered a useful instrument for preliminary static verification of existing external R.C. beam-column joints with smooth rebars