Damage Identification of Timber Bridge Using Vibration Based Methods

Abstract

In recent years, a great deal of attention has been paid to the declining state of the aging infrastructure around the world including Australia. The ability to detect damage at their early stage can reduce the costs and down-time associated with repair of critical damage with enhanced safety and reliability of infrastructures. In this paper, development of a dynamic based method for localization and quantification of damage in timber bridges is presented with an analytical verification of the method using a numerical model updated with experimental data. Algorithms of global non destructive evaluation for identifying local damage and decay in timber structures are investigated. The proposed method is based on changes in modal strain energy of a damaged and an undamaged structure. In this study, the investigation focuses on the capability and limitations of the proposed algorithms for detecting damage in a multimember timber structure as well as on the reconstruction of mode shape from limited sensor inputs. As a result of this investigation, a modified algorithm is proposed to overcome the shortcomings of the original method. In addition, a recommendation has been made in order to reconstruct the mode shape from limited sensor inputs.