The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges. 1. Introduction In the past decade the construction of cable-stayed bridges has increased and their span lengths are growing due to improvements in design and analysis technologies. However, the complex structural characteristics of long-span cable-stayed bridges cause difficulties in understanding their dynamic behavior and make them vulnerable to dynamic loadings from phenomena such as wind or earthquakes. In recent years, many experimental and analytical investigations have studied effective factors on the dynamic behavior of cable-stayed bridges, such as natural periods, mode shapes, and damping properties [1–5]. The sensitivity analysis is a promising way to provide a tuned analytical model and assess the actual dynamic characteristics of superstructures such as cable-stayed bridges. Sensitivity analysis is a technique to determine the influence of different properties, such as boundary conditions, damping properties, material constants, and geometrical parameters, on the structural responses. A number of sensitivity methods for model updating purposes have been proposed for different structures [6–12]; there have been successful applications of sensitivity-based updating technology for bridges in recent years. Cantieni  and Pavic et al.  were among the first to investigate the model updating of bridges using the sensitivity method. Mackie and Stojadinovi？  conducted a sensitivity study to
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