Model Updating of Semirigid Jointed Structure Using Generic Parameters

Abstract

Semirigid connections are usually found in large-scale engineering structures, and the knowledge of the dynamic characteristics of these connections is important to the accurate definition of the dynamic characteristics of the engineering structure. Different models have been presented to define the connection, but most of them are not suitable for model improvement from dynamic measurements of the structure. This paper presents a hybrid finite-element model that consists of a beam element with two semirigid connections at the ends for updating the finite-element model of the jointed structure. The parameter selection strategy of the generic element is adopted, and the stiffnesses of the joint in three dimensions are selected as generic parameters to be updated simultaneously with other structural parameters of the structure. The proposed method is applied to the model updating of a 3D steel truss in the laboratory. Results show that the method could improve significantly not only those vibration modes used in the updating but also the higher modes with a maximum error of 6%.