Finite element modeling of a full-scale five-girder bridge for structural health monitoring

Abstract

Finite element modeling is commonly used to simulate the effect of damage on in-service bridges to facilitate the study of vibration-based damage detection techniques. This study describes the field testing and finite element modeling of an in situ, full-scale, five-girder bridge that is subjected to controlled levels of known damage. The focus of the study is finite element (FE) model calibration to enable the study of damage scenarios including those not imposed during the field tests. Modal parameters are extracted from triaxial vibration records obtained over a relatively dense measurement grid using inexpensive geophones and are used to calibrate a three-dimensional FE model of the bridge. The calibration process and considerations that should be made during field tests for proper model calibration are discussed. Various vibration-based damage detection techniques are evaluated based on their ability to locate the simulated damage. Results show that most of the damage detection techniques evaluated are capable of successfully locating the induced damage on a global level. It is observed from the present study that the horizontal vibration response of the bridge is particularly sensitive to the simulated damage. It is recommended that efforts be made to measure a bridge’s horizontal vibration response (in addition to vertical vibration records) during field tests and this information be included in the FE model calibration processes.