Determination of the Effective Stiffness of Half-Open Cross-Section Bars and Orthotropic Steel Deck of a Truss Bridge Using Model Updating

Abstract

Vibration-based model updating is widely accepted as an effective technique to construct a baseline model for structural health monitoring. In this paper, the effects of half-open cross-section and orthotropic deck on the global vibration behaviour of a truss bridge are considered. To do that, an FE model using ANSYS is built with variations of half-open cross-section area of bars and the stiffness of the orthotropic steel deck. The cross-section area of bars are assigned a reduced coefficient, less than and equal to one. Based on a vibration test, a hybrid optimization algorithm, known as Hybrid Particle Swarm Optimization and Gravitational Search Algorithm (PSOGSA), is applied to reduce the differences in frequencies and mode shapes between measurements and FE simulations. Finally, the effective coefficients of the cross-section as well as the stiffness of steel deck are obtained from the updated model.KeywordsModel updatingHybrid particle swarm optimization and gravitational search algorithm (PSOGSA)Double-decked bridgeHalf-open cross-section