Model Updating of a Reduced-Scaled Masonry Bridge by Using Response Surface Method

Abstract

Historical structures reflect the historical and cultural properties of countries and alsocontributes to the economy in terms of cultural tourism. Therefore, it is important tounderstand the structural behavior of these kinds of structures under dynamics loadssuch as earthquakes, etc. to protect and transfer them safely to future generations. Forthis reason, this study aims to investigate the dynamic behavior of a reduced-scaleone-span masonry arch bridge constructed in laboratory conditions by performing experimentaland numerical analysis. Operational Modal Analysis (OMA) Technique wasperformed under ambient vibrations for experimental study to determine modal parametersof the reduced-scaled bridge model. Sensitive three-axial accelerometerswere located on critical points on the bridge span and signals originated by accelerometerswere collected to quantify the vibratory response of the scale bridge model. Theexperimental natural frequencies, mode shapes and damping ratios resulting fromthese measurements were figured out by using Enhanced Frequency Domain Decomposition(EFDD) technique. ANSYS software was utilized to carry out 3D finite element(FE) modeling of the reduced-scale masonry bridge and determine the natural frequenciesand mode shapes of the bridge numerically. Experimental results were comparedwith FE analysis results of the bridge. Significant differences appeared whencomparing the results of the experimental and numerical with the initial conditions.Therefore, the finite element model is calibrated by using the response surface (RS)method according to the experimental results to minimize the uncertain finite elementmodeling parameters of the reduced-scale bridge model such as material properties.